Tim,

You might try a 15-6 APC. You may have to order it? Tower doesn't carry it. I never cared for the dual pitch props. I'm old fashioned. The dual props didn't catch on in the U.S. like they did in Europe.

If you take a regular 6" pitch prop and measure it on a pitch gauge, it will only measure 6" pitch from about half way on out on the blade. From half way on in it will get down to about 4" pitch. To look at the 6" pitch prop, this doesn't look correct because anyone can planely see that the angle gets greater as you get closer to the hub? Yes, the angle does get greater, but not greater enough. If you are good at math and do some calculations about the blade angle 1/4 the way out you will find that the 6" prop doesn't have 6" pitch there.

Anyway, the 6" prop will let the 91 stay closer to 9000 and you can develop more power and have better climb when you need it. The prop will also act as a brake at low idle.

Enjoy,

Jim