Just put a set of long tubes on my 67 Fastback s-code 390 car. Currently I am running 2 1/2 inch pipes into a 2 1/4 inch Flowmaster 2 chamber 40 series mufflers. (don't ask why the mufflers are 2 1/4 inch, it's a long story) I want to get a set of mufflers that are have 2 1/2 inch outlet and...