ok im buying a 1972 chevelle not SS with a 454 carb in it does it matter what type of exhuast i put on like i mean can i go buy any exhaust for a chevelle and just put it on or do i need to find one that will go with a 454 and a chevelle?

The exhaust should be for a 72 "A-Body". It doesn't really matter if its a 454, as long as its just the exhaust from the headers/manifolds back. If you are buying headers, then they should be for a BB. 2.5" should be a good size for a street 454. I like the flowmaster 40 series.

Chris