Yea a .75 would make that thing move. I'm not too worried about speed but I do need more climb out power and the .68 has the power just need to get the prop right. I would like to stay with a three blade so there is the real problem. I just took the 12-8 3 blade Graupner off and put a 13-8 3 blade Zinger on. Have not flown it yet (raining) but I think this will do it. The big problem right now is getting the Zinger inside a spinner? I'm looking at a special order Tru Turn for about $80 unless anyone has a better solution?