I'm looking into buying a downpipe set that has 3.5" diameter but i'm not sure how well it will fit with the Y pipe which has 3" diameter in the twin pipes and 3.5" when twin pipes connect each other for the main pipe. Any company producing a midpipe that has 3.5" twin pipes connecting to a 3.5" main pipe ? doesnt sound right to bolt 3.5" downpipes with 3" twin pipe sections.