Willys Americar 442-91632-I
This block is serial # 442-91632-I and is a WW2 638632 casting. Willys produced up to # 92020 in 1942.
Notice it looks like the last digit 2 was stamped over a 1.
Cast date is 8 -13.
Notice the Assembly date. You can barely make out what appears to be 11 28 41.