The block number should be on the passenger side just below the head, the alternator might make it hard to see if it’s on that side. The older 396 engines had numbers that gave the horsepower by the distributor passenger side. If you could tell the service manager at a Chevy dealer could tell you. I just thought I took it for granted it was a Chevy, maybe not though.

The newer engines, I'm lost so maybe another member can give you a better idea. Good luck, it's a pain to have an engine running hot.

Richard