Second Generation (1970–1981)

The second generation appeared for the 1970 model year as a mid-year introduction on February 26, 1970 - but was officially designated by Pontiac as a 1970 model, not a 1970 1/2 as many sources have reported through the years. Replacing the coke bottle was a more swoopy body style, with the top of the rear window line going almost straight down to the lip of the trunk lid. This body style was the longest-serving, initially with a large C-pillar until 1975; from that year, the rear window was enlarged. A substantial slant-nose facelift came in 1977, redone in 1979. From 1977 to 1981, the Firebird used four square headlamps, while the Camaro retained the two round headlights that had previously been shared by both cars.

The Firebird Trans Am with the 455 engine was the last high-performance muscle engine of the original muscle car generation. The 455 engine first made its appearance in 1971 as the 455-HO. In 1973 and 1974, a special version of the 455, called the SD-455, was offered. The SD-455 used the left over components from Pontiac's 366 NASCAR engine and was built as a full bore racing engine producing over 540 horsepower and was then toned down to appease the EPA and to meet GM's strict horsepower policy which required all GM vehicles to hold the HP to under 300. As a result, the PMD engineers listed the SD-455 at 290 hp but in reality, was producing in final form, 371 hp SAE NET (Approx 440 gross horsepower). What made this engine unique was the ease with which it could be returned to its 500+ horsepower form. The SD-455 is often considered the last of the true muscle car engines and, by many, considered to be the most powerful factory Pontiac engine ever produced. Pontiac offered the 455 for a few more years, but tightening restrictions on vehicle emissions guaranteed its demise. The 1976 Trans Am was the last of the "Big Cube Birds" with only 7,100 units made with the 455 engine.

The 1981 Turbo Trans Am featured a 4.9L Turbocharged V8 Engine known as the 301T

The 1974 Firebird Formula, optioned with a 400 in³ engine and 4-bbl carburetor

In 1974, Pontiac offered the 400, 455 and SD-455 in the Trans Am. The 400 and 455 engines were the only other option in the 1975 and 1976 models. In 1976 Pontiac celebrated their 50th anniversary, a special edition of the Trans Am was released. Painted in Black with Gold accents, this was the first anniversary Trans Am package and the first production Black and Gold special edition. In 1977, Pontiac offered the T/A 6.6 Litre 400 (option W72) rated at 200 hp, as opposed to the regular 6.6 Litre 400 (option L78) rated at 180 hp. In addition, California and high altitude cars received the Olds 403. The Olds engine offered slightly higher compression and a more usable torque band than the Pontiac engine in 1977. Beginning in 1978, Pontiac engineers reversed years of declining HP numbers by raising compression in the Pontiac 400 through the installation of different cylinder heads with smaller combustions chambers (from the Pontiac 350). This bumped HP by 20 for a total of 220 for 1978-79. The 400/403 options were available until 1979. The 400 cubic inch engines used in 1979 were only available in the 4 speed transmission Trans Ams and Formulas and were stockpiled from 1978. 1979 was the 10th anniversary of the Trans Am and a special 10th anniversary package was available. It was painted silver with a silver lether interior. The 10th anniversary cars featured a special hood bird which extended off of the hood and onto the front fenders. PMD cut production of the engine at the end of the model year in 1978. In 1980, because of ever increasing emissions restrictions, Pontiac dropped all of its large displacement engines.

The 1977 Firebird Trans Am: one of the more popular Second-Generation models 

1980 saw the biggest engine changes for the Trans Am. The 301, offered in 1979 as a credit option, was now the standard engine. Options included a turbocharged 301 or the Chevrolet 305 small block. The 301 was so underpowered that during filming of the second "Smokey and The Bandit" film, the car (Trigger II) had to be equipped with nitrous just to get the car to spin tires.

The final year of the second generation Trans Am, 1981, still used the same engines as the previous year with the only changes being the addition of a new electronic carburation system.

1981 Turbo Trans Am