Why has nobody answered the revised question? there are 2 plugged port on the waterpump. One on top and one on the side. Is there a difference in these, one is 3/4 and one is 1/2". ok my new 4 core radiator didn't come with a place for the heater core to go to. so upon recomendation I"m running it to the waterpump. but...the top has a 3/4" plug, and I can't seem to find a 3/4" M NPT to a 3/4" hose barb anywhere in this town. any ideas? I've been to LOWES, HOME DEPOT, several parts stores, other hardware stores. I"m lost.