THE 1970 PONTIAC GTO




1970 was a pivotal year for Pontiac because for the very first time, GM lifted the restriction of the economy engine (400 CID) and a new 455 cid high output V8 engine was now offered in the mighty GTO.

The 455, a long-stroke engine also available in the full-size Pontiac line was dubiously rated by Pontiac as only moderately stronger than the base 350 HP 400 cid and less powerful than the 366 hp Ram Air III. The camshafts used in the Ram Air III and the GTO 455 HO were the same spec.

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 1970. "Orbit Orange" became the new standard color but any GTO color was available for buyers. Striping was relocated to the upper wheelwell brows.

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 an optional variable-ratio power steering choice. 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 only 3.5 turns lock-to-lock.

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 and 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. The 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. Only a few very-early '70 GTOs could be ordered with this option. 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.

The Ram Air III could accelerate from 0-60 in 6 seconds and could cover a quarter of a mile in 14.7 seconds, topping at 98 mph. The RA IV acceleration was similar but it could cover a quarter of a mile in 14.4 seconds.

The RA IV equipped Judge was even better – it finished its quarter mile in 13.2 sec and accelerated 0-60 in 5.7 sec topping at 104 mph. Competition

For 1970 only 3,797 The judge GTOs were built. Of those, 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 engine, a no-cost option.

The 69/70 Round-Port Ram Air IV engine was the most exotic high-performance engine ever offered by Pontiac and factory-installed in a GTO or Firebird. The 1969 version had a slight advantage as the compression ratio was still at 10:75:1 as opposed to 10.5:1 in 1970. It is widely speculated that Pontiac was losing $1,000 on every RA IV GTO and Firebird built and the RA IV engine was highly under-rated at 370 hp.

Overall, only 37 Ram Air IV GTO Convertibles were built in 1970: 24 4-speeds and 13 automatics. Of the 13 1970 GTO RA IV/Auto Convertibles built only six received the Judge 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 426/440.




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