My freind
Don't cheat yourself forget about all those big engines they are to heavy. they are also not reliable . All you need is a good 4 stroke 120 saito Or os max with a 15x7 prop. You are just looking for a bad time they reb up to much and create to much torqe.My GeeBee has a saito 120 in it. It came in at 12lbs.4oz it was clocked at 85 mph. more than good enough.I also have a expert on board ignition it cuts off at qurter trottle.It makes my old saito purr at low speeds.If thier is one thing you don't want it's a flame out. 1/2 oz in the tail is all i needed to ballance the plane All the gas engine guys are going to have a bad way to go. The geebee just dose not need it.My name is Andrew .I have some input to articles above you make those chages and you will enjoy your GeeBee.A modeler For a long time Andrew