The 1973 Pontiac Firebird Trans Am
Why It's Special:
Back in 1964 the Pontiac Motor Division of General Motors ushered in the muscle car era with the release of the now legendary Pontiac GTO. The basic formula was simple, jam a full size engine into mid-size car, throw in some Rallye wheels, bright stripes, radioactive paint colors, a hood scoop or three and voila, you had a muscle car. It seems fitting then that almost ten years later Pontiac would offer the last true muscle car, the ultra rare Firebird Trans Am SD-455.
Under the Hood:
What a difference two letters can make, and in this case the ‘SD’ or Super-Duty says it all. This specified the 7.5 liter, 455 cubic inch LS2 Super-Duty V8 engine, which packed at whole lot of punch. The comedians at Pontiac rated the engine at 290 horsepower and 390 ft-lbs of torque, although it didn’t take long before the cat was out of the bag.
Initial road tests showed a fully loaded, 3960 pound SD-455 with an automatic transmission capable of 0-60 mph in 5.4 seconds and could run the quarter mile in 13.54 seconds at 104 mph! The National Hot Rod Association eventually rated the engine at 375 horsepower for competition use, a far cry from the 290 horsepower Pontiac claimed.
When the Super-Duty was torn apart it was easy to see where all this power was coming from. A reinforced engine block was fitted with oversized main bearings, forged connecting rods, forged aluminum pistons, high-flow exhaust manifolds, velocity and swirl-ported cylinder heads, oversized valves, a dual plane intake manifold and on top of everything sat a massive 800-cfm Rochester Quadrajet carburetor.
The engine even came from the factory with provisions for a dry-sump oiling system, something rarely seen on today’s best sports cars. Anyway you look at it, the Super-Duty 455 was a race engine de-tuned for street use. Completing the drivetrain was either a Turbo-Hydramatic 400 automatic or Muncie M20 wide-ratio 4-speed manual and a Safe-T-Track limited slip differential.
All this muscle was backed up with plenty of attitude on the exterior. 15 inch Rallye wheels, front and rear spoilers, a massive shaker hood scoop and quite possibly the best decal in automotive history, the “Screaming Chicken”. When the 1973 model year production ended 46,313 Firebirds were produced and a scarce 252 Trans Am Super-Duty 455’s had been built, 72 with manual and 180 with automatic transmissions.
The Verdict:
While there was no denying that the muscle cars were on the out and economy was in, for 252 very lucky owners of 252 very special Pontiacs the legendary era lived on for one more year.
// Comment on this story //