Engine Identification

The numbers stamped into the block under the cylinder head are the serial number of the block. That may come in handy. It could help identify the date of manufacture.

I'm thinking once you get the data on the engine, the best source for tune-up specs would be Mopar Performance. As I recall, these are all Magnum motors with carburetors. By the time the Magnum rolled out, Mopar had moved to TBI or MPFI. None of the books in general circulation would have tune-up specs for a 4-bbl Magnum.