Mike, here a the other casting numbers, passenger side of the block. Guessing the casting is D= December,8=8th, 6=1936 ?? which would make sense for a ‘37 production engine but contradicts my source of information on block numbers.
Larry Old man᠁Old truck᠁neither one goes very fast. All you need in life is TIME, PATIENCE and MONEY. If you are missing one component, you'll need an abundance of the others two.