There's something about that 12.25-3.75 prop that works great for 3D. The blades are wide. It hovers my Ultra Stick 40 all day long with the 46FX. I think my RPMs are only about 10,600 to 11,000. With a 10-7 it would turn almost 12,000. Anyway, with a tuned pipe or Tower muffler you might get the peak more near 12,000 with the 12.25-3.75. Higher nitro would help with the transition and peak RPM's. I'm only running 15% Omega.