Not plate related, but make sure to squeeze the upper radiator hose on the engine while the engine is cold and not running. Make sure that the owner has run the engine up to operating temperature the previous day. If the hose is hard after it has sat overnight, the head is cracked and/or the gasket is blown. If you can squeeze it without any problems or resistance, everything is good.

This is a very important test, be sure that you do it, as a new head will cost you thousands of dollars if the original one is cracked.