The engine in question was Pontiac's largest displacement V8, the 455-ci (7.5-liter), which debuted a year earlier in standard and HO (High Output) forms. Now available for the Firebird Formula ...

The 455 V8 was Pontiac's top-of-the-line large displacement engine in its powerful muscle cars of the '70s. Iconic names like the Pontiac GTO Judge and the Buick Grand Sport also used variations ...

Between 1968 and 1970, Buick joined two of GM's other divisions in unveiling 455 cubic-inch V8s. Oldsmobile was first with its Rocket 455 engine, and Pontiac and Buick both followed suit in 1970.

There's a brutish elegance to this era of Firebird. An SD-455 was tested by Car and Driver in May 1973 and was declared, with a certain amount of sadness, "the last of the fast cars." This 455 ...

This 455 couldn't match the Super Duty's performance when stock, as its L75 7.4-liter engine was rated at just 250 horsepower when new. Bring a Trailer ...

This 455 couldn't match the Super Duty's performance when stock, as its L75 7.4-liter engine was rated at just 250 horsepower when new.

The Pontiac 455 Super Duty, commonly shortened to the 455 SD, is cited by some as one of the last big American muscle car engines. Like many of Pontiac's engines, there were several variants ...

This was still a very serviceable muscle car engine. The 455 HO Pontiac V8 from 1971 was listed from the factory jetting a (probably underrated) 335 gross horsepower and 480 lb-ft (651 N⋅m) of ...