Wow,
It seems like the results are in. I'd really need something with a solid idle and smooth transition. Even if it meant sacrificing a little power on the top end. I have found both motors NIB. Rossi 90-48, OS 91 small and large head. The last thing I really feel like doing is fooling with carburetors and such. I'm a fuel it up and fly type of guy. I don't want to be tinkering around under the hood at the field.
I've had great luck with OS in my pattern planes. Break them in really well, start right up and fly a full tank. In fact my last King Kobra I flew for two years I didn't ever have a single dead stick. Too bad I dumb thumbed it in. RIP.
I'll mull it over for another week before I make my choice. But I'm leaning heavy towards the OS now. Thanks guys.
RickP