Believe it or not a Bisson OS 160 pitts muffler will bolt right on a G-62. I had to side mount aG-62 in my Wilga to hide the engine. For awhile I used a modified Bennett muffler. That didn't hold up as well as I wanted. I had a Bisson OS 160 muffler laying around, and just tried it. The port is very very close, and the bolt pattern is close enough as well. The G-62 has the open ended bolt slots which allows some wiggle room. It runs great, no loss of power, although I did cut both crimps off the ends of the pipes to alleviate the back pressure issues that the 160 likes.