Cam is now on the workbench, and has R stamped on the back end. another noticable item is the unusual (to me) shape of the combustion chambers. apparently the combustion takes place only directly below the valves with a small angled area where the spark plug is. The side opposite the plug and valves has no 'chamber' at all. Other findings are that the pistons are STD., and light honing marks are visable on the cylinder walls. Any information greatly appreciated. Skeet