Flathead Fords were not made by GM, so you can forget everything you think you know about date codes.
The only flathead engines that have explicit dates stamped on them are SOME late ('49-'53) models. Check this link :
https://myflatheadford.com/5988-2/. It will tell you how to interpret the date code stamped on the intake manifold surface if your engine has one.
It really doesn't matter much, as all 8BA series blocks are very similar, one difference being some have valve seat inserts and some don't (there are a few others that don't really matter much). With an engine this old, who knows what might have been done to it.
The important thing is the crankshaft. It may have a Ford 3 3/4" stroke crank or perhaps the more desirable 4" stroke Mercury crank. Everything else is a matter of the components in that particular engine and their condition.