Wow thanks for all the interest...Ricks first two-bits had a McCoy .35 in the front and a .29 in the rear. .65 was the max size at that time.. with 10/6 props. The props are counter rotating and I see no movement from P factor or gyroscopic pressesion. The rear prop can touch, but it takes off and lands in such a neutral attitude that prop strikes are not a problem. Interseting idea from Rush, I do run two timers and ESCs and could delay the start of the rear motor. The possiblilties are endless, I can even have the pusher prop in front and the tractor in the rear. On a side note in 1966 Rick, Tony Nacarado and I took my dads 1963 1/2 ford gallaxy 500 to the Chicago nats on route 66, My gladiator in a box on the roof, scale and carrier planes in the trunk, and the poor guy in the back seat had to hold two-bits on his lap..Great times...thanks dad for trusting a 16yr old. Bob