I'm replacing the head on my CB500 due to some broken fins and a leak. I bought a new head on Ebay and it came with a cam and a valve cover too. I pulled the head off my motor last night and found that my current cam is stamped differently than the one I received. The original has R6 on one side and CP inside a box on the other side. The Ebay cam has R4 on one side, a circled J underneath, and a 5 or an S circled on the back. I don't have a micrometer to check for lobe differences. Could it be that the head I got was from a later model 500 or could one of these be an aftermarket cam?
