The cam is the same from 22re to 22r the only difference is that the 22r cam has a lobe on it right begind the distributor gear, that is used to power the mechanical fuel pump. It does not effect anything though. My thought is that the new radiatior got clogged by debris in your "new" engine's coolant lines, same thing happened to me when i put in a junk yard engine. There was just a bunch of rust and scale clogging up my radiatior that was previously a great free flowing radiator. I got a new one, and it has been going great ever since.