The 455 Super Duty version of the 1974 Pontiac Firebird Trans Am is widely considered to be the last of the original high-performance muscle cars. As the restrictions on engine emissions became ever more stringent the compression ratios dropped, power output plummeted and 1/4 mile times increased for the first time in decades.
The last holdouts in this long battle with environmental legislation were the engineers at Pontiac, who somehow managed to get the performance version of their 455 cubic inch (7.5 litre) V8 approved for production – a feat many considered impossible.
This Super Duty engine featured a strengthened cylinder block with 4-bolt main bearings and additional iron in certain stress points for increased strength. A nodular iron crankshaft was used with enhancements over the stock version, the connecting rods and pistons were made from forged aluminium and the cylinder heads had been re-designed to increase flow.
In early 1973 the Trans Am 455 Super Duty was road tested by the boffins at Car and Driver, to say they loved the car would be a significant understatement. They took the car to the Orange County International Raceway in Irvine, California for 1/4 mile testing and managed a best time of 13.751 seconds. Needless to say they were very impressed with the performance – especially considering the fact that their test car was fitted with an automatic transmission.
In 1974 Pontiac built just 212 examples of the Trans Am 455 Super Duty, there were a few reasons for the relatively low numbers but perhaps first and foremost was the effect of the 1973 Oil Crisis. Gasoline prices had shot up to unheard of levels which had resulted in 7.5 litre V8s suddenly looking a little excessive.
The car you see here is a recently restored 1974 Pontiac Firebird Trans Am 455 Super Duty in its original factory colour scheme with its original matching numbers engine and chassis. It’s not known how many of the 212 cars from this model year have survived but its unlikely there are many that present as well as this one, if you’d like to add it to your own collection it’ll be selling at the Barrett-Jackson Las Vegas Auction on the 24th to the 26th of September 2015.
If you’d like to read more about the car or register to bid you can click here.
Articles that Ben 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.