1970 Pontiac GTO

The 1970 Pontiac GTO, dubbed 'The Humbler' in Pontiac's ad copy that year, successfully continued the GM A-Body derived long hood, short deck design that was introduced for 1968. The GTO received detail improvements, both inside and out, going into 1970, maintaining the premium road-car stature within the Pontiac model line.

The 400 cubic-inch V8 engines continued in several levels of tune, including the 366 horsepower Ram Air III and 370-horsepower Ram Air IV, supplemented by the debut of the new 455 V-8 mid-year. The 'Ram Air' was a highly engineered cold air induction system to provided abundant cool air to the hungry engine. Experimentation with the cold-air induction system had begun in 1963 on Chevrolet's Z11 setup and proved quite effective before corporate demands shut down the program. In 1965, however, Pontiac began offering an over-the-counter Ram-Air system, which caught the attention of the competition who soon had their own versions. Pontiac's continued development, led by Steve Malone, brought a new version using a unique four-way air induction system with heavily massaged tunnel-port heads, known as the fabled Ram-Air IV. Introduced in very limited numbers for 1969, many knew of this advertised 370 horsepower option which was available in any GTO, even the 'Judge.' Even with the introduction of the big-block 455 for the 1970 model year, the small-block V-8 with this with Ram-Air IV was still very popular.

The mythical Ram Air V version was built to withstand the punishment of 7,500-to-8,000-rpm blasts in racing tune and was available in crate form from Pontiac at a cost of approximately $2,000 before installation, representing about half the cost of an entire, well-equipped GTO from the dealer showroom. It was intended primarily for racing and installed in only a few cars. It had intake ports similar to Ford's 302 tunnel port heads, and to minimize any disruption of airflow, had pushrods running through them in streamlined tubes. All of Pontiac's Ram Air engines used mirror ports, with two intake valves in the center of the head. Improved exhaust spacing allowed for large ports and better flow resulting in increased power. Production of the Ram Air V was limited following the SCCA's homologation rule changes for 1970, the declining muscle car era, and Pontiac's source for performance connecting rods went bankrupt.

Handling on the 1970 GTO improved thanks to a new rear anti-sway bar (basically the same used on the Buick Gran Sport and the Oldsmobile 442) and computer-selected coil springs, and the speed-sensitive power steering varied the degree of power assist to ease parking effort while maintaining good road feel at speed. The new system varied its steering ratio from 14.6:1 to 18.9:1, needing 3.5 turns lock-to-lock, down from four turns on the prior fixed ratio of 17.5:1. The standard engine continued to be the 400 cubic-inch four-barrel V8 with 10.25:1 compression and 350 horsepower at 5,000 RPM.

The hidden headlights of the previous year's model were deleted in favor of four exposed round headlamps flanking the grille with narrower openings. The protruding vertical prow theme in the front continued, although it was less prominent. Its siblings, the tempest and LeMans, had chrome grilles while the GTO continued to use the Endura urethane cover around the headlamps and grille.

Pontiac built a total of 40,149 examples of the GTO for 1970, of which 3,797 were factory-equipped with 'The Judge' package, which added wild fender stripes, psychedelic emblems, silver-painted Rally II wheels without the usual trim rings, and a full-width pedestal-style rear spoiler. Orbit Orange (actually a bright canary yellow) became the new feature color for the 1970 Judge, but any GTO color was available, and the striping was relocated to the upper wheel-well brows. The original Tri-Power 1964 GTO is subtle compared to the striped, winged 1970 GTO Judge with the Endura bumper integrated into the body, and the 60-inch airfoil on the rear deck lid. The Ram Air III came standard on the judge, while the Ram Air IV was optional. The Judge, being a GTO first and foremost, delivered excellent performance and the confidence to back up its wild image and conclusively proving the GTO was still the 'Great One.' A Super Stock & Drag Illustrated magazine road test of a 1970 Judge with the Ram Air IV engine reported a 13.60-second quarter-mile time at 104.5 mph through the traps.

Sales of The Judge did not take off as had happed with Plymouth's Road Runner, with 6,833 examples built for 1969 and 3,827 a year later. Overall Sales of the GTO, however, were still fairly healthy at 87,684 for 1968 and 72,287 for 1969. A cheaper economy muscle car than The Judge was still available, by selecting a base GTO with the top engine option. A large drop in GTO sales occurred in 1970, with 40,149 examples made including 3,797 of The Judge. Of the 6,833 Judges made in 1969, a mere 108 were convertibles. This figure actually increased slightly to 168 in 1970. Some sources state 162 examples were built, however, it is believed that six of the 168 examples were equipped with the 1970-only D-Port 455HO engine, a no-cost option. The 1969 and 1970 'round-port' RAM IV engine was a derivative of the 1968 1/2 'round port' RA II engine, with the 1969 version using a 10.75:1 compression ratio compared to 10.5:1 in 1970. Pontiac installed 37 examples off the RA IV in convertibles in 1970, divided between 24 with the four-speed manual transmission and the remaining 13 with the automatic transmission (six with the Judge option). The RA-IV option included '614' heads on the stock RA-IV Block, the '273' carburetor, factory aluminum intake manifold, and the 400 cubic-inch V8 delivering 370 horsepower.

The 1970 Pontiac GTO with the 455HO and Ram Air Induction produced more torque and horsepower equivalent to the Ram Air IV engine. The 4550HO 'YA' code was a new option, available now that GM had rescinded its earlier ban on intermediates with engines larger than 400. The 455HO, a long-stroke engine also available in the full-size Pontiac line as well as the Grand Prix, was dubiously rated (for insurance rating purposes) 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. The same engine installed in the Grand Prix model, per period Pontiac brochures, rated the spec 455HO at 370 horsepower. The camshafts used in the Ram Air III and the GTO 455 HO were the same, and it used the same 288/302 duration cam as the Ram Air III. Factory literature described the 455HO as producing 360 horsepower at 4,300 RPM, and 500 lb-ft of torque at 2,700 RPM. A functional Ram Air scoop was available. Car Life Magazine tested a 455 with Turbo Hydramatic, which clocked 14.76 seconds at 95.94 mph, with identical 6.0 second 0-60 mph acceleration as Car and Driver's test. Both were about 3 mph slower than a Ram Air III 400 four-speed, although considerably less temperamental. The Ram Air III engine idle loped roughly and was difficult to drive at low speeds and not user friendly.

While the 455 cubic-inch engine 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. Pontiac installed 4,146 examples of the 455 HO into the GTO for 1970, with similar figures of 4,644 examples of GTO equipped with the 400 Ram-Air III. 804 examples had the 400 CID V8 with Ram-Air IV induction.

The vacuum operated exhaust (VOE) option was new for 1970 and was vacuum actuated via an underdash lever marked 'exhaust'. This was a short-lived option, offered from November of 1969 to January of 1970, designed to reduce exhaust backpressure and to increase power and performance, but it also substantially increased exhaust noise. GM's upper management ordered Pontiac management to cancel the VOE option following a TV commercial for the GTO that aired during Super Bowl IV on CBS on January 11, 1970. The commercial was entitled the 'Humbler' and broadcast only that one time. In the commercial, a young man driving a new 'Palladium' silver with a black bucket interior GTO pulled into a drive-in restaurant with music and exhaust noise playing in the background. The car had the under-dash 'Ram Air' knob just to the right of the VOE knob, and it wore '1969 Judge' stripes, one of the few very-early 1970 GTOs so equipped. It also had Rally II wheels, air conditioning, hood tachometer, a new-for-1970 Formula steering wheel, remote mirror, and a Turbo Hydra-Matic transmission. He pulled the 'exhaust' knob to active the VOE and then left the drive-in after failing to find a street racing opponent. The commercial was canceled by order of GM management, as was the VOE option. Pontiac equipped approximately 233 GTOs with the option including 212 hardtop coupes and 21 convertibles, all were 'YS' 400ci 350 hp with either four-speed manual or Turbo Hydra-Matic transmissions.

The GTO's declining sales were attributed to the punitive surcharges levied by automobile insurance companies often resulting in dramatic increases in insurance premiums, and increased muscle car options from other manufacturers. In keeping with the vision of former Pontiac Motor Division chief John DeLorean, the 1970 GTO continued as a leading performer while exuding class and character.

The base GTO had a factory price of $3,265 and the convertible listed for $3,500. The hardtop with the WT-1 Series 242 'The Judge' option listed for $3,600 and the convertible at $3,830.

by Daniel Vaughan | Jan 2021