Why do you want a rough idle? The WOW factor? I'd rather have the engine run and make power than impress someone standing on the curb with my idle sound.

The GMPP Hot Cam has a bit of a lope, and you can tell that the engine is "cammed." It's very streetable and will put a roller-cammed Gen I with fast burn heads easily over 400 HP.

It will do the same thing with an LT-1 with good heads and the right setup.