LT1 radiator hoses
 

I bought a used w.p. housing that was already set up for an electric water pump and never looked at it...now that its on the car ive noticed that 3 of the holes have been blocked off. 2 of them arefor the heater core(no biggie i just ziptied those 2 hoses out of the way), and a third runs from the drivers side bottom of the radiator to the pump...this one's a small diameter(like the heater hoses) so i plugged it and ziptied it out of the way.

now i have 2 large radiator hoses going to my water pump. Im curious what the purpose is of that third small diameter hose is??? because if i dont need it ill plug the hose up at the radiator and fuhghedaboutit...but if its important than i need to probably pick up a new housing.

as of now the t-stat was not opening so i ripped it out to await the new one from summit, which should get here tomorrow...could that third hose have something to do with opening the stat up?

The small diam hose on the Driver's side runs to the Radiator or Oil cooler is so equiped. I would think you need it to help pull coolant from down there.