Hey all, I'm going to buy an OS 55AX and I want to know what the best speed and 3D props are for this engine? I'm at 670 ft. above sea level(I've been told that affects performance). I'm giong to put it in a H9 Twist 40 and I'd like a good prop for hovering and one for scooting around fast doing rolls and loops. I currently own an 11x7 prop for my old engine, and was wondering if that would also work for this new one?