In Corvettes, the L-89 is a 427, with aluminum heads and a 3x2 intake, rated at 435 hp. The engine in the Revell '69 Corvette is supposed to be the L-89. The L-71 is basically the same set up, but no aluminum heads and is rated at 400 hp. The L-88 is pictured in a post above and was factory rated at 430 hp. These set ups were available from the factory from 1967 to 1969.