ORIGINAL: PylonDave
I think the motor of choice in the warbird racing is the YS 110
That would be for Gold. And he would have to make some significant airframe mods to handle it.
I run a YS 63 FZ in a TWM Dago Red 46 that is the same size. Same wing, stab, fin. Just a fiberglass fuselage that is the same size. It would barely be a Silver class plane. But it is fun and it sounds really cool without the muffler. I run an APC 11x7 and get about 120 mph with it.