I made the maiden flight on mine yesterday.
OS 32F
APC 9x6
slimline pitts muffler

I mounted the engine with the cylinder horizontal and the exhaust going down. The cowl had to be relieved slighty for the muffler chamber and opened for the head and needle valve. I was able to balance with no extra weights.
It climbed out strong at half throttle, made two ovals around the field and then landed. After seeing some stains silouetted on the inside of the cowl, I checked the engine and found oil and metal shavings around the drive washer. Looks like the front bearing is gone soooooo... picked up a 32SX at the LHS and just finished mounting. Will fly again tomorrow!!!