Muscle Car Drive

1973 Pontiac Firebird Trans Am

The 1973 Pontiac Firebird carried the styling from the 1972 Firebird. Some minor exterior changes included a new egg crate styled grill and redesigned endura bumpers. A new addition to the exterior styling of the 1973 Firebird was the large bird decal which covered the entire hood of the Trans Am. This memorable and appeciated "screaming chicken" decal is well known by car lovers everywhere.

The highlight of the 1973 Pontiac lineup had to be the Super Duty Trans Am or SD-455. This was a venerable beast of a car which could strike fear into the most powerful of muscle cars. The "X" coded Trans Am received a one year only high performance 455cid motor which featured a reinforced engine block including addtional main webbing support, forged crank, forged aluminum pistons with massive 7/16 rod bolts, carefully engineered intake and 800cfm carburetor, and a set of special high performance heads. These heads were the key to making smog legal power in the Trans Am. This included a specialized new manufacturing process which allowed thinner port walls, swirl polished valves, and attention to detail. The results were a highly effiecient cylinder head that made tons of torque and horsepower. This all added up to a car capable of mid 13 second quarter mile times at 104mph.

1973 Firebird Trans Am 455

Firebird Logo Screaming Chicken

As with previous years, the Firebird was available with the Turbo 350 automatic or the Rock Crusher M22 (with Hurst Shifter). Firebirds were also available for the first time with the Radial Tuned Suspension

The SD-455 Trans Am was likely the last great vintage muscle car. It wouldn't be until the mid 1980's when car companies would start to create similarly performing vehicles such as the Buick Grand National and Corvette ZR1.

Production Information:

Base Firebird:14,096
Esprit Firebird : 17,249
Formula Firebird: 10,166
Trans Am: 4,802
SD-455 Trans Am:252 (72 M22, 188 auto)


Base, Esprit, Formula, Trans Am

Powertrain Options:


Cid HP Info
350 150 base
400 170 R code
455 255 Y code
455 310* SD-455

* Net rated at 310hp. However, it is reported to be closer to 370 hp.

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