I have not checked the block serial number, but I'm almost positive it does match.

Gots to check to be sure, too many years between for someone to change things... obviously your finding that out.

Is Superior Pontiac still around?

Really? LMAO.. they dont sell pontiacs anymore... NO! Maybe under a different name, but it isnt called "Superior Pontiac"

I need to check my radiator and see if I have the right one now, thanks.

If all the tags are missing, you will have a hard time telling if it is the original.