[JP1738]

Hey everybody, quick question on a particular combo:

I've been looking through the guide and trying to sort out what I could and couldn't use for a combo for my wagon. I have a block on hand that I could potentially use for a 350 combo, but I can't figure out if the casting number is the right one or not.

It has casting number GM 3970014. I can't find anything in the guide that lists what the stock casting number would be, only after market replacement stuff. Can I use this block for a '79 350 combo? I can't find much of anything on the internet about this particular casting and I don't know how it can be used in terms of class racing. Is that block kinda like Q-jets where one particular casting can be used across the board for lots of years and combos? Please help!