RE: GP minnow/OS91 surpass..what prop
Dave, I think you mis-read this like I did......
Its a surpass 91 - 4c
Erick you may want to play with here is something more like a 13x8.
You want to get the pitch up, diameter down, and try to find the right rpm needed for the engine.
Smaller diameter means a bit less drag.
So something like the 13x8 or even a 13x10 might be worth trying. Either should keep the engine up near 9000-10000 ground rpm.