The block casting number is sometimes under a ridge and forward of the fuel pump making it hard to see. That's where I found my 3701481. I've read where you can lay a piece of paper on it and rub it with a dirty, greasy finger and get the number transferred.

"Hidden" block casting number.




1948 3/4-Ton 5-Window Flatbed Chevrolet

34 Years. Now with a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.