This is a 495 cubic inch (8.1 liter) stroker V8 that was pulled from a 1977 Pontiac Firebird Trans Am. It was then given a comprehensive rebuild in January of 2025, and it’s now being offered for sale.
This rebuild included the fitment of an Eagle rotating assembly, an Edelbrock Performer RPM intake manifold and cylinder heads, a Howards camshaft, a Quick Fuel Technologies four-barrel carburetor, and Pontiac-branded valve covers.
The 1977 Pontiac Firebird Trans Am would shift the 400 cubic inch V8 into the top spot, displacing the earlier 455 V8 which was now no longer able to keep pace with emissions regulations. Image courtesy of Pontiac.
This engine started life as a 400 cubic inch (7.45 liter) Pontiac V8, this was the T/A 6.6 RPO W72 engine that was now the top-of-the-line choice after the 455 V8 had been discontinued a year earlier on emissions grounds.
In stock trim, this engine was good for 200 bhp at 3,600 rpm and 325 lb ft of torque – that horsepower was far down on what similar displacement engines had been making just a few years earlier – thanks to lowered compression ratios and more restrictive tuning to meet federal emissions standards.
As a result of this, the aftermarket was soon offering various go-faster parts and some garages offered full engine rebuilds to claw back all that lost power – though they had to be careful to stay on the right side of the law, lest the Feds came knocking.
The engine shown in this article was pulled from a 1977 Pontiac Firebird Trans Am that was reportedly consuming excessive oil. It was given a full rebuild, and it now has new piston rings, valve seals, and a new rear main seal.
The bores were also honed, the crankshaft was polished, and as mentioned higher up, it was given an aluminum Edelbrock Performer RPM intake manifold and cylinder heads, an Eagle rotating assembly, a Howards camshaft, an MSD distributor, billet aluminum pulleys, and more.
The engine shown in this article was pulled from a 1977 Pontiac Firebird Trans Am that was reportedly consuming excessive oil. It was given a full rebuild, and it now has new piston rings, valve seals, and a new rear main seal.
The work was completed by Mach Machine of Forest Hill, Maryland, in January 2025. The engine also comes with TH400 3-speed automatic transmission, a torque converter, a polished alternator, a flex plate, and a pair of tubular steel exhaust headers.
The engine and transmission, and other parts, are now being offered for sale out of Bel Air, Maryland at no reserve on Bring a Trailer, and you can visit the listing here if you’d like to read more about it or place a bid.
Images courtesy of Bring a Trailer
Articles that Ben Branch has written have been covered on CNN, Popular Mechanics, Smithsonian Magazine, Road & Track Magazine, the official Pinterest blog, the official eBay Motors blog, BuzzFeed, Autoweek Magazine, Wired Magazine, Autoblog, Gear Patrol, Jalopnik, The Verge, and many more.
Silodrome was founded by Ben back in 2010, in the years since the site has grown to become a world leader in the alternative and vintage motoring sector, with well over a million monthly readers from around the world and many hundreds of thousands of followers on social media.
