Dave and all others who see this - I posted further comments earlier but they aren't appearing so I'll try again.

Will be glad to post pictures of the Nomad when it's done, but that won't be for a while since I haven't received the kit yet and I plan to stretch the project out to fill those cold, snowy days when it's no good for flying.

Meant to mention in the priginal post that in addition to the great experience that I'm having with the YS 63S, there's another aspect that I dind't mention previously - the weight savings. Yep, in changing from the OS 61FX with a Mac's Muffler on it to the YS 63S with the stock YS muffler there was a weight savings of ~4 ounces. Since the Mac's muffler weights ~3 ounces less than the stock OS muffler, there is almost 1/2 pound weight savings when going from the stock OS 61FX to the YS 63S.

When you think about this in the context of the plane that I'm going to build, the power of the YS 63S pair will be more than needed. Since the recommended power for the plane is either a pair of .61 2-strokes or .91 4-strokes, it means that the old way of thinking - that "you need more cubic inches and take a weight penalty when changing from a two stroke to a four stroke" - isn't true when a YS engine is the one to which you are changing.