Norbe,
For God's sake and for the sake of all your flying buddies, don't even think of getting the Brison muffler for your engine. They are little more than exhaust diverters and the noise will drive everyone crazy. I don't know who else makes mufflers for that engine but I assure you the noise will be a topic of discussion at your flying field unless you fly way out in the boonies. Brison mufflers are a piece of (^%