Exhaust pipe size

Plan for the future..use 2.5" pipe. the only issue may be the flange on the driver's side manifold..getting a 2 1/2 " pipe to the 1 7/8 hole can be a pain..so your exh guy may go smaller right at the manifold, then go to larger pipe. If you are running headers in teh future, this is no big deal..if you are going manifolds the whole way, it's a big deal..