1974 Trans Am SD-455

We all know that the last days of the golden muscle cars era had come to an end during the early ‘70s but because of the 1973-1974 Pontiac Firebird Trans AM, that era was extended for another four years.

The Survival Era

Though the years of the original muscle cars were long gone, we should give thanks to a lot of car dealers all over the world like eBayMotors, AutoTrader and Craiglist. Since this is the most accessible place where you can trade cars or buy a completely tired classic car that you can restore.

As the dawn of the muscle car era comes to a close, the last effort of Pontiac’s engineers was the Firebird Super Duty 455 and it came out as the last real muscle car.

The Super Duty engines contributed to the Pontiac’s success in NASCAR and NHRA during the early ‘60s. But because of the monstrous Hemi-powered Plymouth Road Runner, the street machine division of Pontiac has lost their momentum.

The SD-455 Firebird

The SD-455 Firebird

In 1973, they released the SD-455 as an option for the Formula and Trans AM versions of the Firebird. The top selling Camaro of that year with 245-hp was blasted by SD-455’s 310 HP. And that caught the attention of many big block cars that ruled the market.

1973 SD-455 Firebird

The Perfect-handling Firebird

In a letter that Gregg Peterson wrote, he urged the head of the Pontiac Product Planning that they should create a modified car for Car and Driver Magazine. Also, Gregg did this because he wanted to see a competition between Pontiac and the mighty Daytona just like the infamous Pontiac versus Ferrari comparisons of the 1960s.

Gregg was an owner of ’74 Trans Am SD-455. He ordered the car as a present to himself after graduating from GM Institute. Since Gregg was an able Pontiac engineer, he started with the modification of the suspension in 1980. He swapped-in firmer aftermarket dampers after cutting the stock springs. He replaced the car’s rubber subframe bushings with thinner steel ones. He finished the modification by widening the wheels and adding a beefy, oversteer-inducing anti sway bar.

’74 Trans Am SD-455

Gregg made a list of improvements which includes the ported heads, a more aggressive camshaft, and a forged-steel crankshaft that is initially made for a 1963 NASCAR racing engine.

Just like any other modified classic cars, this car has its quirks. It barely clears some bumps and nearly dragging the exhaust, it’s two inches lower than stock. All things considered, the stock Trans AM was already one of the best-handling cars in history. And if you add well-considered adjustments like what they did in this car, it will end up as a perfect car that responds quickly to its racing-style steering wheel.

Here are the specs:

Engine: 7.5 V-8, 290-310 hp, 390-395 lb-ft

Transmissions: 4-speed manual, 3-speed automatic

Suspension, Front: Control arms, coil springs

Suspension Rear: Live axle, leaf springs

Brakes, F/R: Disc/drums

Weight: 3600 lb


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