Packard Forum Index » Pre-War (1899-1942)

I've got a 1937 Sport Coupe. The original engine was replaced in 1947. That engine was removed and a NOS block was purchased from Kanter. All the machine work was done and crank,cam and valve train are assembled. I'm working on the front of the engine and found the water pump that was on the old engine is not the correct water pump. It was cobbled onto the original engine. I'm wondering if the blocks are '38 or newer which seems to be a different water pump.
Can somebody tell me the difference between the two engines so I could get the right pump?