I built the herr p-51 and it WOULD NOT FLY WITH A .061!
ditch the gear, and hand toss! with a .074 you may have enough power to keep it in the air, good luck!
P.S. I built mine LIGHT, cut corners where I could...... should be for at least a 10 size motor....
It built fast went smooth butbesides that I was not happy with it......
L.R.