I just had the bulletin out the other day, but the pad for the hour meter mount was not added till in January or February of 1952 don't remember which for sure. The date on the transmission was the date the transmission was poured and then castings were left to age for a period of time before they were machined. If you ever have the thermostat housing off there will be a month and year stamped there. This is when the head was machined. Also look at the engine number stamped in the right rear flange by where the line to the oil pressure gauge hooks up. Post it to.