I know this is an old thread but I checked my stock exhaust diameter and it is 2.22 inches!!7 inch circumference is 2.2 inches diameter. I ordered wrong size tips because I was.lazy and took internet advise. it might b 2.5 before the y but the tail pipes r 2 and a quarter. gettin super 44s put on soon. will post a vid b4/after. c ya