I will be running a Magnum 91 2 stroke on a Plane I just put together; the Engine Manual calls for 13X6 to 14X8 size Props; before I fly it, I am trying different size and style props on the test stand; so far the best performance was Master Air Screw S-2 14X6 at 12,000 rpm and Bolly Clubman 12.5X8 with the same rpm; what performance can I expect on a APC 14X5 Narrow Pattern Prop and a APC 14X4 Wide Fun Fly Prop; the reason I ask, I haven't used these 2 APC Props and are still in the unopened packages, I am happy with the other Props and I'd rather just return the 2 APC Props if their not going to any better.

Thanks, Doug.