69 Firebird 4.5" Water Pump Conversion
 

I am buying a RARE billet pulley set and in my conversation with rep, he said the 4.5" Flow Cooler water pump will work with the Firebird using the later style water pump pulley. They only have the pulley for the 4" pump in 7' diameter vs the conversion pulley which is 4.5" . To me it seems I have ample room in front of fan clutch for this conversion. Is there anything I'm overlooking or reason I shouldn't do this?