More than 50 years on, the 454 is still the big Kahuna—the largest displacement engine ever bolted into a regular production Chevrolet passenger car. It’s lived a long, useful life since its 1970 model-year introduction, powering trucks, boats, generators, race cars of every sort, and more.
Chevrolet will sell you a new 454 today, ready to run, like the 454 HO with 438 hp and 500 lb-ft of torque or the ZZ454 with aluminum heads, rated at 469 hp and 519 lb-ft of torque. These are technically “Gen VI” engines – the original 454 was designated Mark IV. The new engines have four-bolt mains and forged cranks and rods like the best of the originals, but are updated with roller camshafts and one-piece rear main seals. They’re from the same family as the ZZ427 that Hemmings Editor in Chief Terry McGean installed in Hemmings’ 1969 Chevelle SS396 convertible.
The 1970 LS6 454, factory rated at 450 hp, was exclusive to the Chevelle and the El Camino. It not only gave Chevrolet intermediates more power than the Corvette that year, it was the most powerful engine those cars would ever have. Part of the LS6’s charm was that it wasn’t exotic, but made effortless horsepower and torque. The basic recipe included a four-bolt main block; 11.25:1 compression; rectangle-port heads with 2.19-inch intake and 1.88 exhaust valves; an aggressive mechanical cam, shared with other high-performance big-blocks; and a low-rise aluminum intake topped with a 780-cfm Holley. In ’71 the 365-hp LS5 was the top engine offering in the Chevelle, while Corvette gained an LS6 engine option rated at 425 hp and topped with aluminum heads — thus putting Chevrolet’s sports car back on top of the performance lineup. Interestingly, factory literature shows a 425-hp LS6 454 (with iron heads) as an option for the ’71 Chevelle, but none were sold.