Produced by Pontiac, a division of General Motors, the Pontiac Trans Am was based on the Firebird coupe body style and built on the F-body platform.
The last high-performance muscle motor from the original muscle car generation was the Firebird Trans Am with the 455 motor.
In 1971 appearing first as the 455-HO, the 455 motor was introduced.
The SD-455, a unique version of the 455 was offered I n 1973 and lasted one year. Using the leftover components from Pontiac's 366 NASCAR engine, it was built as a full bore racing engine.
With the ability to produce over 540 horsepower, the SD-455 had to be toned down to satisfy the EPA and meet GM's strict horsepower policy which required all GM vehicles to hold the HP under 300.
Though producing in final form, 371 HP SAE NET, approximately 440 gross horsepower, the PMD engineers listed the SD-455 at 290 HP. The ease with which it could be returned to its 500+ horsepower form was what made this engine so unique.
Some consider this SD-455 to be the most powerful factory Pontiac engine to ever be produced.
Offered for a few more years, the restrictions on vehicle emissions eventually became too much to the producers.
With only a total of 7,100 units produced with the 455 engine, the 1976 Trans Am was the final of the 'Big Cube Birds'.
The Trans Am was a strong effort to appeal to the growing muscle car population in the late 1960's.
The Pontiac Firebird was produced from 1967 until 2002. Both the Trans Am and Firebird were discontinued in 2002, though the body is still utilized in the IROC Racing Series.
The first generation of the Pontiac Trans Am was only available in 1969 and came with an optional handling package called the Trans Am Performance and Appearance Package, named after the Trans-Am Series. The package cost a total of $725.
Because the name was used without prior permission, the SCCA threatened to sue GM. The deal was settled by GM offering to pay $5 per every Trans Am sold.
689 hardtop models and eight convertibles were produced in the first year of production. In the same year, an additional Ram Air IV engine option for the 400 in³ to complement the Ram Air II.
Production of first generation models continued longer than one year, actually totally 17 months. The first generation models were differentiated from the Camaro by its four round headlights compared to the Camaro's two.
The Second generation was available from 1970 until 1981.
From 1982 until 1992, the third generation of Trans Am was introduced.
Available from model years 1993 until 1997, the fourth generation Trans Am offered anywhere from 275 to 305 horsepower as a result of the LT1 Small block aluminum headed engine.By Jessica Donaldson