I used a Magnaflow thats 6in. round by 21in. long with a 2 3/4 in. i.d. in & out tube and stainless steel. Also custom pipes from the stock flang behind the Y- pipe out to the back the hole system hangs nice and high not to be in the way and I made all the pipes as striaght as possible still with the 2 3/4 . The thing sound super with a open throttle and nice and tame while cruising. Cost $270.00 CND. My fuel mileage got better after the install too.