Locomotive,

Got it; understand. Now, do you think all that is because of the larger size, or because of design improvements DP made in regards to moments, etc.?

If the latter, can you be more specific?

<<...Don't put a 91 on it...>>

Yeah, that's what I'm thinking. I've seen a kit-built fly adequately with an OS 91, and the YS definitely has more grunt; but I want more than adequate.

Still, I'm going to rob the servos & rx out of the UCD for this project; why not the engine too? They sell the cowl as a replacement part. If the YS 91 proves to be not strong enough for my tastes, a simple application of Mr. VISA will get me a 120 and a new cowl to fit...

Hmmm...decisions, decisions. But isn't that part of the fun???<G>