muffler

This is designed for a 3 inch in and out. you will need 14" of 4" exhaust pipe to split in half for the edges. the cutouts with the center hole are lined up with the horizontal cut marks. the offset cutouts are the ends. the 2 inner cutouts need 3" pipe cut 3/4 long and welded to the cut outs. the 3x3/4 pipe when welded need to face flow direction.