The 1970 Chevrolet Chevelle SS 454 LS6 was factory-rated at 450 horsepower.
The LS6 was Chevrolet’s high-performance 454-cubic-inch V8, offered as an option for the Chevelle SS. Its official rating was 450 hp at 5,600 rpm, with 500 lb-ft of torque at 3,600 rpm. That made it one of the most powerful American production-car engines of the muscle-car era.
The LS6 used high-compression internals, a solid-lifter camshaft, forged components, a large four-barrel carburetor, and an aluminum intake manifold. Buyers could pair it with a four-speed manual or a heavy-duty Turbo-Hydramatic automatic transmission.
A common mix-up is confusing the LS6 with the less powerful LS5 454, which was rated at 360 hp in the Chevelle. Some modern dyno tests suggest the LS6’s real output was higher, but 450 hp is the period-correct factory figure and the canonical quiz answer.