I am looking at some nice long tube ceramic coated headers on Ebay for a 76 C10 with a 350. My question is this. I already have 2 and 1/2" stainless exhaust and alot of the headers have 3" collectors. Are they made to connect to 3" only or can a reducer to the 2 and 1/2" pipe is Ok and not present any restriction problems. Thanks