Make sure that your lateral or wing tip to tip balance is dead on, this can make ALL the difference inthe world. DO NOT use the engine prop shaft as a forward support for checking this as most engines are not perfectly centered due to the offset thrust that is built into many of these planes.

I put a screw eye in the firewall at the exact center as measured from left to right across the fuse. You can support the rear on the tailwheel bracket as they tend to be centered on the fuse.

I have a seen 1/2 oz. placed on one wingtip totally eliminate rock in a couple of planes. Of course it doesn't always work but it's well worth making sure it's correct because it can help with other maneuvers like loops.