I have a stock 4*60 with a 61FX and APC13x6. It does all the standard aerobatic maneuvers and knife edges (1" added to rudder). The 75 will do fine, but expect it to float a little more on landing. One consideration might be prop clearance - it'll be tougher to nick the 12" or 13" prop on the .61FX than a 14" prop on the .91 four stroke