Got a 50 3600 that came with a 235 in it. When I run the numbers it turn out to be 1956 235. The head is stamped 848. In the swap meet there is a reference to a high compression head 848. What do I have? Is 848 a different head than normal. I currently have motor/trans out to do work on de-rusting frame and repairing fire wall and floor. I had no plans to work on the motor since it runs good and doesn't smoke. While I have mtr. out I was going to pull the pan and clean out any gunk in there. Any thing else I need to do? I back flushed the cooling system before I pulled out the mtr. and will take radiater to shop to be rodded out