Does anybody know the difference between KH cylinders / heads and KHK cylinders / heads? And how to identify them? I have a '56 KHK with pretty screwed up cylinders and am considering putting some other KH's I have on it. But if the cylinders that came off it are KHK and worth the effort I might repair them. The parts book lists different part numbers but I've compared and I can't see much difference. Any thoughts?