The muscle car era gave up the ghost sometime in the very early 70s. Environmental controls strangled it. But a band of Pontiac engineers put on some moves.

They built the fastest Pontiac ever. Now one of these ultra rare birds is coming to auction.

By 1972, with performance plummeting, sales of the Firebird had plunged. The Trans Am’s 455 was rated a tepid 300 horsepower.  But in 1973, there was a stirring, a resurgence.

Two things happened.  The appearance of the large “screaming chicken” hood graphic.  And introduction of the 455 Super Duty engine, shockingly close to a race engine, appearing when every other performance car was disappearing into grey mediocrity.


How did Pontiac get this high-powered Super Duty engine past the suits?  It took a cabal of engineers and a complicit engine-plant foreman who hoarded parts.  They passed the engine off as just another 455 engine that already existed and therefore didn’t have to meet the higher standards posed for new engines.  But that wasn’t nearly the truth!

The SD-455 V-8 had a reinforced block, special cam shaft, aluminum pistons, oversize valves and header-like exhaust manifolds.  A well-kept secret is that all the Super Duty engines were hand-built race engines… an off-assembly-line operation.  .


Car & Driver in its road test of a 1973 SD-455 Trans Am, said,

“…the best compliment bestowed on the Firebird is the fact that, even in its own time, it is becoming a collector’s item.”

To get the kind of performance the Super Duty could produce, you had to go all the way back to the euphoria of 1968. Think of the street hemis, the L88s, the Boss 429s.   But the Oil Embargo suppressed sales and the screaming Trans Am SD-455 was a seriously endangered species… limited to just 212 made.

Barrett-Jackson will have a pristine example of one of the 212 Trans Ams with the Super Duty engine up for auction in Las Vegas September 24, with no reserve.

See below if you would like a print of the 1973 Trans Am 455.  Artist Eric White specializes in performance cars.