The serial number I gave (T3795778) is stamped into the flat spot just behind the distributor. I couldn't find any cast numbers. Some of the posts I searched through said it's by the starter, but I just don't see anything there. Does the starter maybe have to be removed to see it? The only cast marking I can see on the block is 'GM', which is below and just in front of the distributor.
Here's one more piece of the puzzle. I just noticed that Chevs of the '40s has a pump that
appears to be just like my old one,
here , but it says that it's for a '39 or '40. Might my engine be older than the truck?
