manks,

I'd run the 10 X 7.5 threeblade and see how it does. The 10 X 6 or the 10 X 5 is going to turn up alot more. The 11 X 9 IMO is just to much prop and the 11 X 4 ????? Whatever your choice is remember you control the throttle. So a flatter pitch is OK the speed of the airplane will be slower, but the takeoff and climb enhanced. Just don't run at full throttle all the time with a lower pitched prop if you don't need the power. Power management is a great tool once learned.