I've had both, forged internal,supercharged full bolt on LT1, and mild bolt on nitrous LS1, I can tell you first hand.......LS1>LT1. With a lid and mass air sensor I can remember atleast 4-5 head cam LT1's that I beat. Ls1 is close to a full second faster from the factory and mod for mod, dollar for dollar, the LS1 is the LT1's daddy...not to mention way more reliable. I rate the LT1 in the same class as Fords 2V modular motor.......