I had a 1960 Willis Jeep that had the "F" head. Remember it well. Burned an exhaust valve which was in the block. The intakes were in the head. Could have been from poor maintenance. Never adjusted the valves. Just changed oil and filters and drove it quail hunting. The rest of the time it sat under the barn. Rugged little machine. I remember the old WW2 Jeeps having a"L" head with all the valves in the block.