Rattler cams are for street enthusiasts who want the classic exhaust sound but also want true performance to go with it. These camshafts offer performance that just doesnt thump around. They give you the performance and throttle response you expect from a performance cam. Dont let the others fool you, sound is not everything. If you want both sound and performance, you need a Howards Cams Rattler. The best of both worlds. Note: To get the best exhaust note, you should use a good dual exhaust system without a cross-over. A cross-over will add minor performance, but mellow the exhaust tone.