I had a souped up Homelite 25cc on my Ultra Stik Lite 120 with a smoke system and it flew great. (Right up until I "dumb thumbed" it into the ground on a low inverted pass one day....) A Homelite 30cc weighs the same and would work great on your USL. Should have more power than the Mac 32 as well.</p>

Can't answer your question about the two different engines. I only have experience with the older ones. Could you post pics?

Re your original question and my recommendation, that's a combo that I have been thinking of doing myself just to have a simple, cheap, fun plane to take with me when I travel, or for "day to day knock around" use.</p>

AV8TOR</p>