Ok, so now i have changed out the thermostat, and water pump (after having to drill out and retap a hole because a bolt broke). And now the pulley I have sits too close to the fins on the pump and is rubbing, how in the world is this possible. I bought the correct one checked all the part numbers from every parts store in town and even checked with a chevy parts counter to be certain. My question is do I need to get a different water pump (don't really want that this one is on there good and sealed). Or can I get a set of shims for it? The pump that came off the engine was the factory pump.

1983 firebird
173 2BBL V-6 (2.8)
All Stock.