I have built several engines that the head has been shaved,ported and polished. The engine runs fine, no problems. Always replace the cam chain anytime you rebuild a Honda 600 engine, do it right the first time and the engine will take care of you. I have a Z600 in the shop now, with the Hawaiian head,cam, and exhaust, Sudco Carb, the engine was rebuilt four years ago, still running strong.
wizardoneout