your better off with a mac's muff. the thunder tiger, or super tigre 55......75 might fit. call mac's and get the bolt spaceing. or go to tower and look at mac's pipes. they give you the bolt space on there mac's muffler. these are called piece pipe mufflers. the black ones .they work very good and are more streamlinded that os type or super mufflers. there not that costly either. put 5 min epoxy on the muffler flange,and red locktite # 271 on the bolts before installing. let it set overnite, before starting the engine. use just enough epoxy to coat the flange,don't slop it on. wipe the excess that squeezes out ,off with alky. the muff will stay on for months of flying this way............RON . remember that old saying........no muff's to tough.