2 1/2" or 3"

Not knowing how much power the engine is making, 2-1/2 exhaust pipe is alot quiter than a 3 inch system. Some people argue over exhaust tube size for best power or streetablity. I stay with the exhaust companies recomendations that over 450 HP, a 3 inch system will (In most cases) deliver the best power.

Sound control becomes an issue with a bigger sound outlet. Think bigger the speaker, the more sound. Of course, muffler choice has a major roll in this. I've seen and heard a glass pack replace a muffler on a slant 6 sound like holy heck was breakin loose. (Oh wait, that was my aear drum breakin)