You might do a search for Memphisbelle's posts on the US 41. I bought his YA P47, which has a US41. It provides completely adequate scale flight, with great big loops, four point rolls, etc. I like it because, with the custom exhaust he built, the cowl is complete, no holes.

He had this engine in a 4-Star 120, and hovered with it. Another of his current planes is a Dynaflite Chipmunk with another US41, and it quite aerobatic. For the money, it's hard to beat this engine.

Good luck,
Dave Olson