The Chevelle SS 454 LS6 is frequently called the fastest factory muscle car ever built and the claim is defensible. The 450 horsepower rating was honest — possibly conservative. The 500 lb-ft of torque is the specification that matters for a street car.

The LS6 was available only in 1970 and only in the Chevelle. Cowl induction, solid lifters, four-bolt main caps, aluminum intake, and the largest available carb. It was designed to go fast in a straight line and it accomplished that purpose completely.

A documented LS6 Chevelle is a significant investment. The number of fakes and upgrades exceeds the number of originals by a substantial margin. NCRS documentation, broadcast sheets, and expert inspection are all necessary before paying LS6 money for any car claiming to be one.