I am replacing my water pump and the new one I purchased has a small hole at the top left looking from the front that intersects with a hole in the block. The old pump didn't have this hole,which one is correct?another question I have is the water pump has 2 - 3/4 inch hose fittings and the thermo housing has one,I realize 2 of these go to the Heater circuit but what about the third one,the cylinder head was off when I purchased the truck,and I didn't see how it was plumbed.
