As in F4U Corsair? That's not exactly a plane that one would choose for doing aerobatics. I don't fly 3D but there are quite a few inexpensive foamie's that do exactly that. One that comes to mind is 'The Bug' at www.lightflite.com It's an odd looking thing but is really capable.

More is needed to know what prop you should use. Weight is a key factor. How much does that corsair weigh with engine, ESC, batteries, and servos installed?

CGr.