Maybe a better question was "what do you want for it". Good score.
Now I guess you have checked over the sides of the casing and there is no sign of a casting date.
What about the winters snowflake, any sign of SYC, stamped there??
Turn the block over, upside down, does it have any stamped numbers in the machined surface, these may only be a small numeric number not the alpha numeric codes you normally think of. If you got the caps, did they have any numbers stamped in them.
Finally clean the block on the inside, and get a good flashlight, and someone with vision a lot better than mine, and look for anything else stamped in the block.
Porterfield told me the same and it was amazing what turned up.
Finally after getting "acquainted with your new toy, how hard is it going to be to give it up ?????