Thanks for the suggestions. I had planned on a 14x4 prop, but the hobby shop here did not have one in stock. I chose a 13x5 for now... it was either that or a 14x6 (our shop here has limited stock). I have some 14x4's on order. The plane flew well this weekend with the GMS 76 and the 13x5, but I think I will like the 14x4 a little better. But then again with my flying, I may never notice the difference! ha! By the way, the 76 allowed me to balance the plane with 0 dead weight. I know the 76 may be more motor than needed, but better too much than not enough... besides you don't have to fly full throttle all the time. Vertical was unlimited and I was careful not to open the throttle all the way in a dive or downwind flying... a fellow club member's UCD 46 exploded in air yesterday during a full throttle pullout from a steep dive (OS 50sx). Looks like the fuse gave way around the wing saddle and the plane exploded (it was actually quite spectacular). He should have know better, the UCD is just not designed for the way he was flying it. Oh well, lesson learned.