i had a 440 source water pump in my '69 coronet r/t stocker which is an edelbrock clone. my car always ran hot (all iron and 22" radiator) but ran exceptionally hot with that style of water pump. I installed a 6 blade (large diameter blades with an anti-cavitation plate) pump in place of the 440 source and the water temps went down 15-20 degrees. I think those edelbrock/440 source pumps are garbage. there's a 10 blade pump out there; I think flow-cooler.