The Pontiac GTO is an automobile built by Pontiac Division of General Motors in the United States from 1964 to 1974, and by GM subsidiary Holden in Australia from 2004 to 2006. It is considered an innovative, and now classic muscle car of the 1960s and 1970s. From 1964 until midway through 1973 it was closely related to the Pontiac Tempest/LeMans and for the 1974 model year it was based on the Pontiac Ventura. The 21st century GTO is essentially a left-hand drive Holden Monaro, itself a coupe variant of the Holden Commodore.
The GTO was the brainchild of Pontiac engineer Russell Gee, an engine specialist; Bill Collins, a chassis engineer; and Pontiac chief engineer John DeLorean. In early 1963, General Motors' management issued an edict banning divisions from involvement in auto racing. At the time, Pontiac's advertising and marketing approach was heavily based on performance, and racing was an important component of that strategy. With GM's ban on factory-sponsored racing, Pontiac's young, visionary management turned its attention to emphasizing street performance.
In his autobiography “Glory Days,” Pontiac chief marketing manager Jim Wangers, who worked for the division’s contract advertising and public relations agency, states that John DeLorean, Bill Collins and Russ Gee were indeed responsible for the GTO's creation. It involved transforming the upcoming redesigned Tempest (which was set to revert to a conventional front-engine, front transmission, rear-wheel drive configuration) into a "Super Tempest" with the larger 389 cu in (6.4 L) Pontiac V8 engine from the full-sized Pontiac Catalina and Bonneville in place of the standard 326 cu in (5.3 L) Tempest V8. By promoting the big-engine Tempest as a special high-performance model, they could appeal to the speed-minded youth market (which had also been recognized by Ford Motor Company's Lee Iacocca, who was at that time preparing the Ford Mustang).
The name, which was DeLorean's idea, was inspired by the Ferrari 250 GTO, the successful race car. It is an Italian abbreviation for Gran Turismo Omologato, (exact translation is Grand Tourer Homologated) which means officially certified for racing in the Grand tourer class. The name drew protest from enthusiasts, who considered it close to sacrilege.
The GTO was basically a violation of GM policy limiting the A-body intermediate line to a maximum engine displacement of 330 cu in (5.4 L). Since the GTO was an option package and not standard equipment, it could be considered to fall into a loophole in the policy. Pontiac General Manager Elliot "Pete" Estes approved the new model, although sales manager Frank Bridge, who did not believe it would find a market, insisted on limiting initial production to no more than 5,000 cars. Had the model been a failure, Estes likely would have been reprimanded. As it turned out, it was a great success.
The first Pontiac GTO was an option package for the Pontiac Tempest, available with the two-door coupe, hardtop coupe, and convertible body styles. Despite rumors, Pontiac never built a GTO station wagon on its assembly lines. The US$ 296, package included a 389 cu in (6.4 L) V8 rated at 325 bhp (242 kW) at 4800 rpm) with a single Carter AFB four-barrel carburetor and dual exhaust, chromed valve covers and air cleaner, 7 blade clutch fan, a floor-shifted three-speed manual transmission with Hurst shifter, stiffer springs, larger diameter front sway bar, wider wheels with 7.50 × 14 redline tires, hood scoops, and GTO badges. Optional equipment included a four-speed manual, Super Turbine 300 two-speed automatic transmission, a more powerful "Tri-Power" carburation rated at 348 bhp (260 kW), metallic drum brake linings, limited slip differential, heavy-duty cooling, ride and handling package, and the usual array of power and convenience accessories. With every available option, the GTO cost about US$ 4,500 and weighed around 3,500 lb (1,600 kg). A tachometer was optional, and was placed in the far right dial on the dash.
Most contemporary road tests used the more powerful Tri-Power engine and four-speed. Car Life clocked a GTO so equipped at 0–60 miles per hour (0–97 km/h) in 6.6 seconds, through the standing quarter mile in 14.8 seconds with a quarter mile trap speed of 99 mph (159 km/h). Like most testers, they criticized the slow steering, particularly without power steering, and inadequate drum brakes, which were identical to those of the normal Tempest. Car and Driver incited controversy when it printed that a GTO that had supposedly been tuned with the "Bobcat" kit offered by Ace Wilson's Royal Pontiac of Royal Oak, Michigan, was clocked at a quarter mile time of 12.8 seconds and a trap speed of 112 mph (180 km/h) on racing slicks. Later reports strongly suggest that the Car and Driver GTOs were equipped with a 421 cu in (6.9 L) engine that was optional in full-sized Pontiacs. Since the two engines were difficult to distinguish externally, the subterfuge was not immediately obvious. In Jim Wanger's "Glory Days" he admitted after three decades of denial that the red drag strip GTO had its engine swapped to a 421 Bobcat unit. Since the car was damaged during the testing, and Wangers did not want anyone looking under the hood, he used the blue road course GTO to flat tow the red GTO 1500 miles back to Detroit. Frank Bridge's sales forecast proved inaccurate: the GTO package had sold 10,000 units before the beginning of the 1964 calendar year, and total sales were 32,450.
Throughout the 1960s, Ace Wilson's Royal Pontiac, a Pontiac car dealer in Royal Oak, Michigan, offered a special tune-up package for Pontiac 389 engines. Many were fitted to GTOs, and the components and instructions could be purchased by mail as well as installed by the dealer. The name "Bobcat" came from the improvised badges created for the modified cars, combining letters from the "Bonneville" and "Catalina" nameplates. Many of the Pontiacs made available for magazine testing were equipped with the Bobcat kit. The GTO Bobcat accelerated 0-60 mph in 4.6 seconds (this 0-60 time is now equalled by the factory 2005-06 GTO with automatic transmission, fuel injection, and no modifications).
The precise components of the kit varied but generally included pieces to modify the spark advance of the distributor, limiting spark advance to 34-36° at no more than 3,000 rpm (advancing the timing at high rpm for increased power), a thinner head gasket to raise compression to about 11.23:1, a gasket to block the heat riser of the carburetor (keeping it cooler), larger carburetor jets, high-capacity oil pump, and fiberglass shims with lock nuts to hold the hydraulic valve lifters at their maximum point of adjustment, allowing the engine to rev higher without "floating" the valves. Properly installed, the kit could add between 30 and 50 horsepower (20-40 kW), although it required high-octane superpremium gasoline of over 100 octane to avoid spark knock with the higher compression and advanced timing.
The Tempest line, including the GTO, was restyled for the 1965 model year, adding 3.1 inches (79 mm) to the overall length while retaining the same wheelbase and interior dimensions. It sported Pontiac's characteristic vertically stacked quad headlights. Overall weight increased about 100 pounds (45 kg). Brake lining area increased nearly 15%. Heavy-duty shocks were standard, as was a front antisway bar. The dashboard design was improved, and an optional rally gauge cluster ($86.08) added a more legible tachometer and oil pressure gauge.
The 389 engines received revised cylinder heads with re-cored intake passages, improving breathing. Rated power increased to 335 hp (250 kW) at 5,000 rpm for the base 4—barrel engine; the Tri-Power was rated 360 hp (270 kW) at 5,200 rpm. The Tri-Power engine had slightly less torque than the base engine 424 lb·ft (575 N·m) at 3,600 rpm versus 431 lb·ft (584 N·m) at 3,200 rpm. Transmission and axle ratio choices remained the same. The three-speed manual was standard, while a four-speed manual or two-speed automatic were optional.
The restyled GTO had a new simulated hood scoop. A rare, dealer-installed option was a metal underhood pan and gaskets to open the scoop, making it a cold air intake. The scoop was low enough that its effectiveness was questionable (it was unlikely to pick up anything but boundary layer air), but it allowed more of the engine's roar to escape.
Car Life tested a 1965 GTO with Tri-Power and what they considered the most desirable options (close-ratio four-speed manual transmission, power steering, metallic brakes, rally wheels, 4.11 limited-slip differential, and Rally Gauge Cluster), with a total sticker price of US$3,643.79. With two testers and equipment aboard, they recorded 0–60 miles per hour (0–97 km/h) in 5.8 seconds, the standing quarter mile in 14.5 seconds with a trap speed of 100 miles per hour (160 km/h), and an observed top speed of 114 miles per hour (182.4 km/h) at the engine's 6,000 rpm redline. A four-barrel Motor Trend test car, a heavier convertible handicapped by the two-speed automatic transmission and the lack of a limited slip differential, ran 0-60 mph in 7 seconds and through the quarter mile in 16.1 seconds at 89 miles per hour (142.4 km/h).
Major criticisms of the GTO continued to center on its slow steering (ratio of 17.5:1, four turns lock-to-lock) and mediocre brakes. Car Life was satisfied with the metallic brakes on its GTO, but Motor Trend and Road Test found the four-wheel drum brakes with organic linings to be alarmingly inadequate in high-speed driving.
Sales of the GTO, abetted by a marketing and promotional campaign that included songs and various merchandise, more than doubled to 75,342. It spawned many imitators, both within other GM divisions and its competitors.
Pontiac's intermediate line was restyled again for 1966, gaining more curvaceous styling with kicked-up rear fender lines for a "Coke-bottle" look, and a slightly "tunneled" backlight. The tail light featured a rare louvered cover, only seen on the GTO. Overall length grew only fractionally, to 206.4 inches (524 cm), still on a 115 inch (292 cm) wheelbase, while width expanded to 74.4 inches (189 cm). Rear track increased one inch (2.5 cm). Overall weight remained about the same. The GTO became a separate model series, rather than an optional performance package, with unique grille and tail lights, available as a pillared sports coupe, a hardtop sans pillars, or a convertible. Also an automotive industry first, plastic front grilles replaced the pot metal and aluminum versions seen on earlier years. New Strato bucket seats were introduced with higher and thinner seat backs and contoured cushions for added comfort and adjustable headrests were introduced as a new option. The instrument panel was redesigned and more integrated than in previous years with the ignition switch moved from the far left of the dash to the right of the steering wheel. Four pod instruments continued, and the GTO's dash was highlighted by walnut veneer trim.
Engine choices remained the same as the previous year. A new rare engine option was offered: the XS engine option consisted of a factory Ram Air set up with a new 744 high lift cam. Approximately 35 factory installed Ram Air packages are believed to have been built, though 300 dealership installed Ram Air packages are estimated to have been ordered. On paper, the package was said to produce the same 360 hp (270 kW) as the non-Ram Air, Tri Power car, though these figures are believed to have been grossly underestimated in order to get past GM mandates.
Sales increased to 96,946, the highest production figure for all GTO years. Although Pontiac had strenuously promoted the GTO in advertising as the "GTO Tiger," it had become known in the youth market as the "Goat." Pontiac management attempted to make use of the new nickname in advertising but were vetoed by upper management, which was dismayed by its irreverent tone.
The GTO underwent a few styling changes in 1967. The louver-covered tail lights were replaced with eight tail lights, four on each side. Rally II wheels with colored lug nuts were also available in 1967. The GTO emblems located on the rear part of the fenders were moved to the chrome rocker panels. Also the grill was changed from a purely split grill, to one that shared some chrome.
The 1967 GTO came in three body styles:
- Hardtop - 65,176 produced
- Convertible - 9,517 produced
- Sports Coupe - 7,029 produced
The GTO also saw several mechanical changes in 1967. The Tri-Power carburetion system was replaced with a Rochester Quadrajet four-barrel carburetor. The 389 engine received a wider cylinder bore (4.12 inches, 104.7 mm) for a total displacement of 400 CID (6.6 L) V8. The 400 cubic inch engine was available in three models: economy, standard, and high output. The economy engine used a two-barrel carburetor rather than the Rochester Quadrajet and produced 255 bhp (190 kW) at 4400 rpm, and 397 ft·lbf (538 N·m) at 4400 rpm. The standard engine produced 335 bhp (250 kW) at 5000 rpm, and the highest torque of the three engines at 441 ft·lbf (598 N·m) at 3400 rpm. The high output engine produced the most power for that year at 360 bhp (270 kW) at 5100 rpm, and produced 438 ft·lbf (594 N·m) at 3600 rpm. Emission controls were fitted in GTOs sold in California.
1967 also saw the installation of significant safety equipment as required by federal law. A new energy-absorbing steering column was accompanied by an energy-absorbing steering wheel, padded instrument panel, non-protruding control knobs, and four-way emergency flashers.
The two-speed automatic transmission was also replaced with a three-speed Turbo-Hydramatic TH-400. The TH-400 was equipped with a Hurst Performance Dual-Gate shifter, called a "his/hers" shifter, that permitted either automatic shifting in "Drive" or manual selection through the gears. Front disc brakes were also an option in 1967.
GTO sales for 1967 remained high at 81,722.
GM redesigned its A-body line for 1968, with more curvaceous, semi-fastback styling. The previous 115 inch (292 cm) wheelbase was shortened to 112 inches (284 cm) for all two-door models. Overall length was reduced 5.9 inches (150 mm) and height dropped half an inch (12 mm), but overall weight was up about 75 pounds (34 kg). Pontiac abandoned the familiar vertically stacked headlights in favor of a horizontal layout, but made hidden headlights available at extra cost. The concealed headlights were a popular option. The signature hood scoop was replaced by dual scoops on either side of a prominent hood bulge extending rearward from the protruding nose.
A unique feature was the body-color Endura front bumper. It was designed to absorb impact without permanent deformation at low speeds. Pontiac touted this feature heavily in advertising, showing hammering at the bumper to no discernible effect. Though a rare option, a GTO could be ordered with "Endura Delete", in which case the Endura bumper would be replaced by a chrome front bumper and grille from the Pontiac Le Mans. This model year further emphasized the curvacious "coke bottle" styling.
Powertrain options remained substantially the same as in 1967, but the standard GTO engine's power rating rose to 350 hp (260 kW) at 5,000 rpm. At mid-year, a new Ram Air package, known as Ram Air II, became available. It included freer-breathing cylinder heads, round port exhaust and the 041 cam. 'Official' power rating was not changed, although actual output was likely much higher. Another carry-over from 1967 was the 4-piston caliper disc brake option. While most 1968 models had drum brakes all around, this rare option provided greater stopping power and could be found on other GM A-Body vehicles of the same period. 1968 was also the last year the GTOs offered separate vent, or "wing", windows—and the only year for crank-operated vent windows.
Another feature was concealed windshield wipers, hidden below the rear edge of the hood. They presented a cleaner appearance and were a North American first, following British Leyland's earlier debut on Austin and Triumph models. Another popular option, actually introduced during the 1967 model year, was a hood-mounted tachometer, located in front of the windshield and lighted for visibility at night. An in-dash tachometer was also available.
Redline bias-ply tires continued as standard equipment on the 1968 GTO, though they could be replaced by whitewall tires at no extra cost. A new option was radial tires for improved ride and handling. However, very few were delivered with the radial tires because of manufacturing problems encountered by supplier B.F. Goodrich. The radial tire option was discontinued after 1968. Pontiac did not offer radial tires as a factory option on the GTO again until the 1974 model.
Hot Rod tested a four-speed GTO equipped with the standard engine and obtained a quarter mile reading of 14.7 seconds at 97 mph (156 km/h) in pure stock form. Motor Trend clocked a four-speed Ram Air with 4.33 rear differential at 14.45 seconds at 98.2 mph (158.0 km/h) and a standard GTO with Turbo-Hydramatic and a 3.23 rear axle ratio at 15.93 seconds at 88.3 mph (142.1 km/h). Testers were split about handling, with Hot Rod calling it "the best-balanced car [Pontiac] ever built," but Car Life chiding its excessive nose heaviness, understeer, and inadequate damping.
Like all 1968 passenger vehicles sold in the United States, GTOs now featured front outboard shoulder belts (cars built after January 1, 1968) and side marker lights.
Now facing serious competition both within GM and from Ford, Dodge, and Plymouth—particularly the low-cost Plymouth Road Runner—the GTO won Motor Trend's Car of the Year award, and sales remained strong at 87,684 (which would ultimately prove to be the second-best sales year for the GTO).
The 1969 model did not have the vent windows, had a slight grille and taillight revision, moved the ignition key from the dashboard to the steering column (which locked the steering wheel when the key was removed, a Federal requirement installed one year ahead of schedule), and the gauge faces changed from steel blue to black. In addition, the rear quarter-panel mounted side marker lamps changed from a red lens shaped like the Pontiac "V" crest to one shaped like the broad GTO badge. Front outboard headrests were made standard equipment on all GTOs built after January 1, 1969.
The previous economy engine and standard 350 hp 400 CID V8 remained, while the 360 hp (270 kW) 400HO was upgraded to the Ram Air III, rated at 366 hp (273 kW) at 5,100 rpm. The top option was the 370 hp (280 kW) Ram Air IV, which featured special header-like high-flow exhaust manifolds, high-flow cylinder heads, a specific high-rise aluminum intake manifold, larger Rochester QuadraJet four-barrel carburetor, high-lift/long-duration camshaft, plus various internal components capable of withstanding higher engine speeds and power output. Unlike the big-block Chevy and Hemi motors, the Ram Air IV utilized hydraulic lifters.
By this time, the gross power ratings of both Ram Air engines were highly suspect, bearing less relationship to developed power and more to an internal GM policy limiting all cars except the Corvette to no more than one advertised horsepower per 10 lb (4.5 kg) of curb weight. The higher-revving Ram Air IV's advertised power peak was actually listed at 5,000 rpm—100 rpm lower than the less-powerful Ram Air III. The straight stock Ram Air IV's were easily pushing 500 hp (370 kW) with a few tweaks to the carburetor and timing, and utilizing a careful mix of high octane airplane fuel in the tank.
The Ram Air V was introduced in 1969 to professional racing, not for sale to the general public or in showrooms, and was sold and delivered in a crate. It was a special 400 block with newly designed high compression tunnel port heads and a special high rise intake manifold. A prototype GTO so equipped could go 0-60 mph in 5.7 seconds, and the quarter-mile time was 13.89at101.76mph seconds at 123 mph (198 km/h). Ram Air Vs were not installed in GTOs at the factory; it was available only as an "over-the-counter" product for professional racing, and therefore most went to Pontiac racers of the time.
The most significant event of 1969 for the GTO was the launch of a new model called 'The Judge'. The Judge name came from a comedy routine, "Here Come de Judge", used repeatedly on the Rowan & Martin's Laugh-In TV show. The Judge routine, made popular by legendary showman Sammy Davis, Jr. was borrowed from the act of long-time Burlesque entertainer Dewey "Pigmeat" Markham. Advertisements used slogans like "All rise for The Judge" and "The Judge can be bought." As originally conceived, the Judge was to be a low-cost GTO, stripped of some gimmicks to make it competitive with the Plymouth Road Runner. During its development, however, it was decided to make it the ultimate in street performance and image. The resulting package ended up being US$332 more expensive than a standard GTO, and included the Ram Air III engine, Rally II wheels without trim rings, Hurst shifter (with a unique T-shaped handle), wider tires, various decals, and a rear spoiler. Pontiac claimed that the spoiler had some functional effect at higher speeds, producing a small but measurable down force, but it was of little value at legal speeds except for style. The Judge was initially offered only in "Carousel Red," but midway into the model year a variety of other colors became available. Of these other colors, a "Ram Air IV Judge Hardtop" painted in Crystal Turquoise with a black interior is the most rare with only two know to exist, one in Chicago IL, and one in Lenexa KS.
The GTO was surpassed in sales both by the Chevrolet Chevelle SS396 and the Plymouth Road Runner, but 72,287 were sold during the 1969 model year, with 6,833 of them being The Judge. The rarest 1969 GTO, omitting color options, was the Ram Air IV Judge Convertible - only five were built (Year One catalog).
The Tempest line received another facelift for the 1970 model year. Hidden headlights were deleted in favor of four exposed round headlamps outboard of narrower grille openings. The nose retained the protruding vertical prow theme, although it was less prominent. While the standard Tempest and LeMans had chrome grilles, the GTO retained the Endura urethane cover around the headlamps and grille.
The suspension was upgraded with the addition of a rear anti-roll bar, essentially the same bar as used on the Oldsmobile 442 and Buick Gran Sport. The front anti-roll bar was slightly stiffer. The result was a useful reduction in body lean in turns and a modest reduction of understeer.
Another handling-related improvement was optional variable-ratio power steering. Rather than a fixed ratio of 17.5:1, requiring four turns lock-to-lock, the new system varied its ratio from 14.6:1 to 18.9:1, needing 3.5 turns lock-to-lock. Turning diameter was reduced from 40.9 feet (12.5 m) to 37.4 feet (11.4 m).
The base engine was unchanged for 1970, but the low-compression economy engine was deleted and the Ram Air III and Ram Air IV remained available, although the latter was now a special-order option.
A new option was Pontiac's 455 HO engine (different from the round-port offerings of the 1971-72 cars), available now that GM had rescinded its earlier ban on intermediates with engines larger than 400. The 455, a long-stroke engine also available in the full-size Pontiac line as well as the Grand Prix, was dubiously rated by Pontiac as only moderately stronger than the base 350 HP 400 cu. in. and less powerful than the 366 hp (273 kW) Ram Air III. Curiously, per the Pontiac brochure of the time, the same spec 455 installed in the Grand Prix model was rated at 370 horsepower (280 kW). The camshafts used in the Ram Air III and the GTO 455 HO were the same. For example the manual transmission 455 HO's used the same 288/302 duration cam as the Ram air III. The 455 was rated at 360 hp (270 kW) at 4,300 rpm. Its advantage was torque: 500 lb·ft (678 N·m) at 2,700 rpm. A functional Ram Air scoop was available. Car and Driver tested a heavily optioned 455, with a four-speed transmission and 3.31 axle and recorded a quarter mile time of 15.0 seconds with a trap speed of 96.5 mph (155.3 km/h) . Car Life's Turbo-Hydramatic 455, with a 3.35 rear differential, clocked 14.76 seconds at 95.94 mph (154.40 km/h), with identical 6.6 second 0-60 mph acceleration. Both were about 3 mph (4.8 km/h) slower than a Ram Air III 400 four-speed, although considerably less temperamental: the Ram Air engine idled roughly and was difficult to drive at low speeds. The smaller displacement engine recorded less than 9 mpg-US (26 L/100 km; 11 mpg-imp) of gasoline, compared to 10 mpg-US (24 L/100 km; 12 mpg-imp)-11 mpg-US (21 L/100 km; 13 mpg-imp) for the 455.
A new and short-lived option for 1970 was the Vacuum Operated Exhaust (VOE), which was vacuum actuated via an underdash lever marked "EXHAUST." The VOE was designed to reduce exhaust backpressure to increase power and performance, but it also substantially increased exhaust noise. The VOE option was offered from November 1969 to January 1970. Pontiac management was ordered to cancel the VOE option by GM's upper management following a TV commercial for the GTO that aired during Super Bowl IV on CBS January 11, 1970. In that commercial, entitled "The Humbler," which was broadcast only that one time, a young man pulled up in a new GTO to a drive-in restaurant with dramatic music and exhaust noise in the background, pulling the "EXHAUST" knob to activate the VOE and then left the drive-in to do some street racing. That particular commercial was also cancelled by order of GM management. Approximately 233 1970 GTOs were factory built with this rare option including 212 hardtop coupes and 21 convertbiles, all were "YS" 400ci 350 hp/with either four-speed manual or Turbo Hydra-matic transmissions. This particular GTO in the commercial was Palladium Silver with a Black bucket interior. It was unusual in several respects as it also had the under-dash "RAM AIR" knob just to the right of the VOE knob, and it sported '69 JUDGE stripes, as a few very-early '70 GTOs could be ordered with. It also had a Turbo Hydra-matic transmission, remote mirror, Rally II wheels, A/C, Hood Tach, and a new-for-1970 Formula steering wheel. A few 'VOE' mufflers were "Hand-made" for the remaining cars; this occurred in 2006 and 2007, and they are now available from Waldron Antique Exhaust.
The Judge remained available as an option on GTOs. The Judge came standard with the Ram Air III, while the Ram Air IV was optional. Though the 455 CID was available as an option on the standard GTO throughout the entire model year, the 455 was not offered on The Judge until late in the year. "Orbit Orange" became the new standard color for the '70 Judge, but any GTO color was available on The Judge. Striping was relocated to the upper wheelwell brows.
An Orbit Orange 1970 GTO with the 455 engine and Turbo Hydra-Matic transmission was one of the featured cars in the movie Two-Lane Blacktop, which depicted a cross-country race between the new GTO and a 1955 Chevrolet Bel Air. The car, owned by the studio, was not depicted as a Judge; however, in reality it WAS a RAIV powered Judge. They mentioned the 455 engine as it projected a more powerful offering to the public.
The new styling did little to help declining sales, which were now being hit by sagging buyer interest in all musclecars and by the punitive surcharges levied by automobile insurance companies, which sometimes resulted in insurance payments higher than car payments for some drivers. Sales were down to 40,149, of which 3,797 were The Judge. Of those 3,797 Judges built, only 168 were ordered in the Convertible form: RA III, RA IV and 455HO. The general consensus is that six of the 168 built were ordered with the 1970-only D-Port 455HO 360 hp (270 kW) engine, a no-cost option, which explains the conflicting production figures over the years as to how many were built; 162 vs. 168. The '69/'70 'Round-Port' RA IV engine, a derivative of the '68½ 'Round-Port' RA II engine, was the most exotic high-performance engine ever offered by PMD and factory-installed in a GTO or Firebird. The 1969 version had a slight advantage as the compression ratio was at 10:75:1 as opposed to 10.5:1 in 1970. It is widely known that PMD was losing $1,000 on every RA IV GTO and Firebird built, and the RA IV engine was highly under-rated at 370 hp (280 kW). Overall, only a precious 37 RA IV GTO Convertibles were built in 1970: (24) 4-Speeds and only (13) automatics. Of the (13) '70 GTO RA IV/Auto Convertibles built only a precious six (6) received the Judge option. One of those, a #'s-Matching Atoll Blue/Blue/White top example was bid to $240K @ the May 2009 Mecum Auctions in Marengo, Illinois, and did NOT sell. Th low bid was attributed to the stagnant economy, and that particular car is documented back to the original owner in Pewaukee, Wisconsin. The three-speed manual, nor A/C, was not available with the RA IV engine, and the standard axle ratio was 3.90, with the 4.33 being a low-cost option. The GTO remained the third best-selling intermediate muscle car, out-sold only by the Chevrolet Chevelle SS 396/454 and Plymouth Road Runner.
The 1971 GTO had another modest facelift, this time with wire-mesh grilles, horizontal bumper bars on either side of the grille opening, more closely spaced headlamps, and a new hood with the dual scoops relocated to the leading edge, not far above the grille. Overall length grew slightly to 203.3 inches (516 cm).
A new corporate edict, aimed at preparing GM for no-lead gasoline, forced an across-the-board reduction in compression ratios. The Ram Air engines did not return for 1971. The standard GTO engine was still the 400 CID V8, but now with 8.2:1 compression. Power was rated at 300 hp (220 kW) SAE gross at 4,800 rpm and torque at 400 lb·ft (542 N·m) at 3,600 rpm. It had 255 hp (190 kW) SAE net at 4,400 rpm in the GTO and 250 hp (190 kW) SAE net at 4,400 rpm in the Firebird.
An engine option was the 455 CID V8 with four-barrel carburetor, 8.4 to 1 compression ratio and 325 hp (242 kW) at 4,400 rpm, which was only available with the Turbo Hydra-matic TH-400 transmission. It had 260 hp (190 kW) SAE net at 4,000 rpm in the GTO and 255 hp (190 kW) SAE net in the Firebird. This engine was not available with air induction.
The top GTO engine for 1971 was the new 455 HO with 8.4 compression, rated at 335 hp (250 kW) at 4,800 rpm and 480 lb·ft (651 N·m) at 3,600 rpm. It had 310 hp (230 kW) SAE net at 4,400 rpm in the GTO and 305 hp (227 kW) SAE net in the Firebird Trans Am or Formula 455 with air induction. The 1971 Pontiac brochure declared that this engine produced more NET horsepower than any other engine in its history. That would imply the 400 CID V8 Ram Air engines had less than 310 hp net. While rated at 335 hp gross, in order to suggest it had less power than it did, you could say it should have been rated at 375 hp gross to compare with other Pontiac engines. This engine had more NET horsepower than the 1970 455 CID V8 GTO, which was essentially the regular engine found in other Pontiacs with a GTO exhaust system, and was continued in 1971 as the second option above.
For 1971,the standard rear-end was an open 10 bolt. Posi-traction 10 bolt rear ends were available as an option on 400 CI engine equipped GTO's, while all 455 CI GTO's were available with a 12 bolt open or optional 12 bolt posi-traction rear-end.
Motor Trend tested a 1971 GTO with the 455, four-speed transmission, and 3.90 axle, and obtained a 0-60 mph time of 6.1 seconds and a quarter mile acceleration of 13.4 seconds at 102 mph (164 km/h).
The Judge returned for a final year, With the standard equipment being the Mountain Performance package was the 455 HO. Only 357 were sold before The Judge was discontinued in February 1971, including 17 convertibles today the rarest of all GTOs, aside from the 1969 Ram Air IV convertible. Only 10,532 GTOs were sold in 1971, 661 of which were non-Judge equipped convertibles.
In 1972, the GTO reverted from a separate model line to a US$353.88 option package for the LeMans and LeMans Sport coupes. On the base LeMans line, the GTO package could be had with either the low-priced pillared coupe or hardtop coupe. Both models came standard with cloth and vinyl or all-vinyl bench seats and rubber floor mats on the pillared coupe and carpeting on the hardtop, creating a lower-priced GTO. The LeMans Sport, offered only as a hardtop coupe, came with Strato bucket seats upholstered in vinyl, along with carpeting on floor and lower door panels, vinyl door-pull straps, custom pedal trim and cushioned steering wheel, much like GTOs of previous years. Other optional equipment was similar to 1971 and earlier models. Planned for 1972 as a GTO option was the ducktail rear spoiler from the Pontiac Firebird, but after a few cars were built with that option, the mold used to produce the spoiler broke, and it was cancelled. Rally II and honeycomb wheels were optional on all GTOs, with the honeycombs now featuring red Pontiac arrowhead emblems on the center caps, while the Rally IIs continued with the same caps as before, with the letters "PMD" (for Pontiac Motor Division).
Power, now rated in SAE net hp terms, was down further, to 250 hp (190 kW) at 4,400 rpm and 325 lb·ft (441 N·m) at 3,200 rpm torque for the base 400 engine. The optional 455 had the same rated power (although at a peak of 3,600 rpm), but substantially more torque. Most of the drop was attributable to the new rating system (which now reflected an engine in as-installed condition with mufflers, accessories, and standard intake). The engines were relatively little changed from 1971.
A very rare option was the 455 HO engine, essentially similar to that used in the Trans Am. It was rated at 300 hp (220 kW) at 4,000 rpm and 415 lb·ft (563 N·m) at 3,200 rpm, also in the new SAE net figures. Despite its modest 8.4:1 compression, it was as strong as many earlier engines with higher gross power ratings; yet like all other 1972-model engines, it could perform on low-octane regular leaded, low-lead or unleaded gasolines. Only 646 cars with this engine were sold.
Sales plummeted by 45%, to 5,811. (Some sources discount the single convertible and the three anomalous wagons, listing the total as 5,807.) Although Pontiac did not offer a production GTO convertible in 1972, a buyer could order a LeMans Sport convertible with either of the three GTO engines and other sporty/performance options to create a GTO in all but name. Even the GTO's Endura bumper was offered as an option on LeMans/Sport models, with "PONTIAC" spelled out on the driver's side grille rather than "GTO."
Once again an option package for the LeMans, the 1973 GTO shared the reskinned A-body with its "Colonnade" hardtop styling, which eliminated true hardtop design because of the addition of a roof pillar but retention of frameless doorwork. Rear side windows were now of a fixed design that could not be opened and in a triangular shape. New federal laws for 1973 demanded front bumpers capable of withstanding 5-mile-per-hour (8 km/h)impacts with no damage to the body (5 mph rear bumpers became standard in 1974). The result was the use of prominent and heavy chrome bumpers front and rear. The overall styling of the 1973 Pontiac A-body intermediates (LeMans, Luxury LeMans, GTO and Grand Am) was generally not well received by the car buying public.
In contrast, the Pontiac Grand Prix and Chevrolet Monte Carlo, which were also derived from the intermediate A-body, were much better received because of their squared-off styling and formal rooflines with vertical windows. Pontiac's sister division, Oldsmobile, received better reviews from the automotive press and the car-buying public with the similar-bodied Cutlass.
Again, the 1973 GTO option was offered on two models including the base LeMans coupe or the LeMans Sport Coupe. The base LeMans coupe featured a cloth-and-vinyl or all-vinyl bench seat while the more lavish LeMans Sport Coupe had all-vinyl interiors with Strato bucket seats or a notchback bench seat with folding armrest. The LeMans Sport Coupe also had louvered rear side windows from the Grand Am in place of the standard triangular windows of the base LeMans.
The standard 400 CID V8 in the 1973 GTO was further reduced in compression to 8.0:1, dropping it to 230 hp (170 kW). The 400 engine was available with any of the three transmissions including the standard three-speed manual, or optional four-speed or Turbo Hydra-Matic. The 455 CID V8 remained optional but was dropped to 250 hp (186 kW) and available only with the Turbo Hydra-Matic transmission. The 455 HO engine did not reappear, but GM initially announced the availability of a Super Duty 455 engine (shared with the contemporary Pontiac Trans Am SD455), and several such cars were made available for testing, impressing reviewers with their power and flexibility. Nevertheless, the Super Duty was never actually offered for public sale in the GTO. Also, eight 455SD Grand Ams were also built for testing and eventually all were destroyed as well.
Sales dropped to 4,806, due in part to competition from the new Grand Am and the lack of promotion for the GTO. By the end of the model year an emerging energy crisis quashed consumer interest in muscle cars.
Wanting to avoid internal competition with the "Euro-styled" Pontiac Grand Am, and looking for an entry into the compact muscle market populated by the Plymouth Duster 360, Ford Maverick Grabber and AMC Hornet X, Pontiac moved the 1974 GTO option to the compact Pontiac Ventura, which shared its basic body shell and sheetmetal with the Chevrolet Nova. Critics dubbed it "a Chevy Nova in drag."
The $461 GTO package (Code WW3) included a three-speed manual transmission with Hurst floor shifter, heavy-duty suspension with front and rear anti-roll bars, a shaker hood, special grille, mirrors, and wheels, and various GTO emblems. The only engine was the 350 CID (5.7 L) V8 with 7.6:1 compression and a single four-barrel carburetor. It was rated at 200 hp (150 kW) at 4,400 rpm and 295 lb·ft (400 N·m) at 2,800 rpm. Optional transmissions included a wide-ratio four-speed with Hurst shifter for $207 (Code M20) or the three-speed Turbo Hydra-Matic. Power Steering was a $104 option (Code N41) as well as Power front disc brakes for $71 (Code JL2).
The GTO option was available in both the base Ventura and Ventura Custom lines as either a two-door sedan or hatchback coupe. The base Ventura interior consisted of bench seats and rubber floor mats, Bucket seats could be added for $132 (Code A51), while the Ventura Custom had upgraded bench seats or optional Strato bucket seats along with carpeting, cushioned steering wheel, and custom pedal trim.
Bias-belted tires were standard equipment, but a radial tuned suspension option added radial tires along with upgraded suspension tuning for improved ride and handling.
Cars Magazine tested a 1974 GTO with the optional four-speed and obtained a 0-60 mph time of 7.7 seconds and a quarter mile reading of 15.72 seconds at 88 mph (142 km/h).
Sales were an improvement over 1973, at 7,058, but not enough to justify continuing the model.
1975 to 1999Edit
Pontiac had planned to offer a 1975 GTO, again based on the compact Ventura and powered by a Pontiac-built 350 CID V8. The Ventura and other GM compacts underwent substantial styling and engineering changes, the latter including front and rear suspensions similar to the sporty Firebird. In the end, however, the GTO was discontinued following a corporate decision to switch to Buick V8 engines on the 1975 Ventura line, though Pontiac V8s were continued in all other division models. GM management decided that the GTO must end its production run.
In 1975, an enterprising Pontiac dealer in the Eastern United States reportedly decided to "create" a new GTO. Sensing that the 1974 GTO should have continued on the intermediate LeMans platform rather than downsized to the Ventura line, this dealer advertised and sold an undetermined number of 1975 Pontiac GTOs. These cars were factory-ordered by the dealer as LeMans Sport Coupes equipped with the 400 or 455 CID V8s with four-barrel carburetors, Turbo Hydra-Matic transmissions, Strato bucket seats and console, power steering, power disc brakes, Rally II or Honeycomb wheels, and Radial Tuned Suspension with whitewall or white-lettered radial tires. The dealer replaced the Pontiac and LeMans nameplates with "GTO" badges inside and out. This dealer-made 1975 GTO could be ordered with any LeMans exterior/interior combination along with any other extra-cost options available on the regular LeMans.
In 1976, Jim Wangers reportedly presented a LeMans Sport Coupe as a new GTO Judge prototype with a 400 CID V8 that was painted Carousel Red to Pontiac division officials as a possible GTO revival to supplement dramatic sales increases for the Firebird Trans Am (now accounting for 50% of Firebird sales) for those buyers who wanted a sporty performance car but needed a roomier back seat and larger trunk. However, division officials turned down the idea of an intermediate-sized GTO, but the concept was considered and approved for production; not as a GTO revival, but as the 1977 Pontiac Can Am.
During the subsequent 30 years, Pontiac considered several plans to revive the GTO nameplate, but none came to fruition. In 1988, when Oldsmobile planned to create a 442 based on the Cutlass Calais, Pontiac built a prototype GTO based on the Grand Am, equipped with a Quad 4 engine. The revived 442, introduced for the 1990 model year, proved to be a low seller, leading Pontiac to quietly cancel the GTO revival.
Japanese automaker Mitsubishi marketed a GTO coupe, although it was sold in U.S. and Canada as the Mitsubishi 3000GT to avoid legal conflicts with Pontiac. Fans of the original GTO considered the appropriation of a famous muscle car by a Japanese automaker to be sacrilegious, much as sports car fans of the 1960s had been infuriated by Pontiac borrowing the name of the Ferrari racer.