Hi fellas I just got a y-pipe from a 370Z and at the exit it is 2.5" but the two catalytic flanges have 1- 3/4" ID is this alright ? how much is the ID at the outside of our stock catalytic? BTW i have an 2003 coupe 6mt

 

check out this thread with pics to see about measurments https://g35driver.com/forums/intake-...p-y-pipes.html