I did research the Vibrant posts, that is where I got the part number to order. The stock M6 muffler is oval and is about 15" when cut out, the Vibrant replacement is about 12". Most seemed to just drop the car at the muffler shop for the swap, but couldn't find a definite answer as to what material was being used for the 3" added pieces. I guess I could just order some 304 or some 409 stainless pipe and take it to them.