3" or 2.5" exhaust (pics)

I think with your combo Mullinax, 3" would be overkill. Ya got good headers and with good flowing mufflers 2 1/2" will probably be fine. I've always used 500HP as the margin between 3" and 2 1/2", that's why I stuck with 2 1/2" on the 383, it's just shy of 500 HP. My bottleneck are the Schmachers but it doesn't see much track time. It's like Clint says "ya gotto know your limitations".

Terry