The original 1970 LS5 version of the big-block Chevrolet 454 engine produced 390 horsepower that drove the Chevrolet Corvette. The LS6 version produced in the same year and installed in the Chevelle was rated at 450 horsepower.
Chevrolet introduced the large eight-cylinder 454 in 1970 as the successor to the popular 427. The newer engine displaced 453.96 cubic inches and each cylinder had a 4.250-inch bore and 4-inch stroke. Besides the LS5 and LS6 versions, Chevrolet also developed a 465 horsepower version called the LS7 that never went into production.
Following the introduction of stricter emission controls in 1971 and the gas crisis of 1973, newer models of the 454 featured lower horsepower. For example, the 1972 LS5 produced 270 horsepower. The last "LS" series 454 was the LS4. Introduced in 1973, the engine was rated at 275 horsepower.
The large engine powered a number of sports cars and large sedans, including the Chevrolet Caprice, Chevrolet Chevelle, Chevrolet Monte Carlo and GMC Sprint. Although the 454's use in muscle cars declined rapidly after its introduction, the engine was used in trucks such as the GM 2500 and 3500 until 1996.
As of 2014, Chevrolet produces other big-bore 454 engines. Examples include the LSX454 rated at 620 horsepower and the 454HO rated at 425 horsepower.