The most powerful stock 1970 Chevrolet Chevelle SS Z15 produced 450 horsepower with the optional LS6 engine. This is 90 horsepower more than the stock Turbo-Jet 454 engine used in the Z15 trim.
The LS6 engine option in the 1970 Chevelle SS Z15 was the most powerful stock engine ever offered in a 1970s Chevelle model, producing 500 foot-pounds of peak torque. Many Chevrolet fans believe that the official performance numbers for the LS6 are lower than the engine's true output figures. A Chevelle with an LS6 can accelerate from 0 to 60 miles per hour in slightly over 6 seconds.