Which numbers? Casting or serial?
All of the books I've seen for casting numbers, such as the "Chevrolet by the Numbers" series, only cover V-8's, not inlines. That doesn't mean nothing exists, I just haven't found it/them yet, although Brownell's "How to Restore your Chevrolet Pickup" has a page with some casting numbers. There are lots of online resources for inline casting numbers, such as
Inliners. I usually just do a web search for any number in question.
For serial numbers, there are some publications, one of them being "Catalog of Chevy Truck ID Numbers 1946-1972". This particular book only covers the light trucks, though. I have quite a few old Chevy parts manuals, and have amassed many of the inline engine codes for 56-83. Also,
Keith Hardy\'s site contains quite a few of the Chevy resto packs that contain serial number info, including for your '40 truck.
