tdwise

I have a twin .25 A-10 about ready to take flight and before it does, I'd like some input on prop sizes. Presntly, it has 8x6's cut down to 7.25" in order to clear the fuselage and wing. During initial run-up's, I noticed that the RPM's were already well into the 12K range at only about 1/2-2/3 throttle. To me, it appears the props are spinning faster than the air they can grab and was wondering if I could take a larger diameter prop (ie: 10 or 11x6) and trim it down to the 7.25" diameter. Would the "broader" blade surface cause any problems as far as efficiency goes or should I go to a 9 or 10" prop with a steeper pitch (ie: 9x7 or 9x8 if the latter is available)? I also haven't discarded the notion of using 3 blades either. Any feedback is greatly appreciated!

Ted