Centek 1600899 Muffler Port Side fiberglass mufflers are the most popular replacemets for Silverton 34' and Mainship 36'. They replace square galvanized box mufflers and have been re-designed to a lift style muffler, which gives superior noise reduction. Port side muffler (has (2) 3"-in and (1) 4"-out OD exhaust fittings). Replaces Marine Muffler part # XS-SIL-P1716. Order the short muffler mounting kit separately.