Well, I guess it really doesn't matter anyway because what they are is what are. You will probably need to find the dimension at header collector ends so the exhaust can be modified to hook up to the header outlet. There are collector adaptors for doing this but it's up to you to do some carefull measurements so you can attach header flanges to exhaust pipes. PS, when you get the header adaptors, make sure their dimension has the same size as the exhaust pipes and should be welded not clamped. If you don't have the tools to do this(welding) call around for some exhaust repair shops ... they should have no problems to weld up the header adaptors. Jake
A forum community dedicated to all General Motors makes and models owners and enthusiasts running the 3800 series engine. Come join the discussion about performance, modifications, classifieds, troubleshooting, builds, tunes, superchargers, maintenance, and more!