Bill- I agree it looks like a great engine, although some what pricey? The big question though for me is how does it compare power wise to the Moki 2.1.
Apparently you need a fair chunk of nose lead (approx 2 lb+) to balence the P51 with the Moki also, and I do hate to see dead weight in my models, so the Husky could be a good option...

I just wish Y.S. made a 140DZ V-Twin e.g. - Y.S. 280DZ Now that would be perfect!