RE: GP Super Stearman
I have the same set up and had to grind down the front of the adapter to get the dome to fit into the back plate. I also used a plain washer between the adapter washer and the prop. You will have to shorten the bolt that holds the dome to the adapter a little. Have about 15 flights and no trouble with spinner as of yet. G-26 seems to give a good scale flight, enough power for some limited vertical, and crusies about 1/2 throttle. Very happy with plane once I figured how to land it.