Thanks for the input CGR . I`ve flown a Twist quite a bit on high rates and know how squirrely they can be. The thick wing and large surfaces of the SSE reminded me of the Twist . And since the airframe is used at lower speeds , thought a 4c would be better for the mid range torque.
I did run 4 or 5 tanks thru the GMS .47 on the test stand and out of the 15 engines I have , this one seems to have the highest RPM , it just screams , but it`s a lot louder than the others.
The Saito .56 pulled the 4* 200 ft vertical and would hold a knife edge at about 2/3 throttle , so I think it should have plenty of power. If it`s not enough , the .72 fits in the same footprint, just did`nt want to fool with changing landing gear to get prop clearance.
I`m like a kid in a candy store, I cannot make up my mind. I better go flying and think about it. lol