Well I finally have a chance to match up these pipes with headers,The novarossi Rossi 91 header were the same diameter as the AA80/90 Parabolic pipes. I had to do a little brainstorming,To be able to come up with a idea to get pipe to telescope over header a couple of cold beers later bingo perfect. mufflers should be arriving any day now power plants will be completed. Thanks for reading more to come shortly