A Video on The Pontiac Super Duty 455




A Video on The Pontiac Super Duty 455 Engine.

Watch this cool video that compares the standard Pontiac 455 and the Pontiac Super Duty 455.


In 1973, Pontiac introduced the Super Duty 455 engine it used a similar camshaft specification to the Ram Air IV 400.  The engine was rated at 310 Hp but failed to pass EPA Emissions test. Pontiac de-tuned the engine to 290 HP by using a cam profile similar to the 73 to 74 Ram Air III 400 engines and a lower 7.9:1 compression ratio.

An evolution of the 455 Ho the SD 455 was a racing engine, de-tuned for passenger car production. The SD engines came with High Flow Round Port cylinder heads, reinforced lifter galley, 4-bolt main bearing, forged connecting rods, forged-aluminum pistons and additional material in various locations for improved strength.

1973 Pontiac Trans Am SD 455 Engine

1973 Pontiac Trans Am SD 455 Engine



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The Supper Duty 455 was available on the Pontiac Trans AM or Formula Firebird in 1973 and 1974 only. The Engine was “under-rated.” at 290 Hp with 7.9:1 compression ratio.

In 1973 the EPA Implemented stricter smog regulations. While most manufactures to put their muscle cars on the chopping block, Pontiac Surprised everyone by introducing the SD 455 Firebirds and Trans AM. Pontiac’s Special Projects engineers developed their new Super Duty 455 performance engine as if it would be their last. The SD 455 immediately acquired near-mythical status that has never faded.

Pontiac placed the Super Duty 455 under the umbrella of the standard 455 family of engines. But, the SD 455 was something very special, not just a modified 455.


Super Duty 455 Trans AM

1973 Super Duty 455 Trans AM





1973 Firebird Trans Am 72 180 252
1973 Firebird Formula 10 33 43
1974 Firebird Trans Am 212 731 943
1974 Firebird Formula n/a n/a 58
TOTAL n/a n/a 1,296


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