This is gonna sound absolutely dumb, but here it is: What is the path of the water. Does the water pump push the water into the bottom of the radiator and then push it out the top of the radiator into the intake or the reverse direction of pulling the water from the bottom of the radiator and pushing it up through the engine and out the intake returning it into the top hose. I just installed my rebuilt 305 and added a serp belt set-up and a TPI system. The car IMMEDIATELY OVERHEATS, within 1-2 minute of start up the temp gauge is pegged. The thermostat is open. There is water in the intake. The water neck housing is not wet at all and the radiator hose is almost perfectly dry. I kept the water neck off and left the thermostat out, took the end of the upper radiator hose and put it in the bucket. I turned the key over and no water is coming from the upper radiator hose, it is being pushed out the intake where the thermostat would be. I appreciate the help on the flow path and any ideas.

 

Every Gen. 1 SBC has the same coolant flow direction:

Out the bottom of the radiator
Into the pump
Into the block
Up to the heads
Up to the intake
Back the top of the radiator

The difference between V-belt and serpentine water pumps is the direction of the impellars inside the water pump (goes by rotation - either standard or reverse, V-belt is standard, serpentine is reverse).

Sounds to me like you have a serpentine setup with a standard rotation water pump. You need a serpy water pump.

 

Even though when I turn the engine over it pushed the coolant out the intake hole where the thermostat would be. Doesn't that sound like the water pump is pushing the water up the block like it should be going?
Tony

 

What pump did you use?

 

Should have explained that I did buy a new pump for the set-up from autozone. I told him it was for a serp set-up and he got me the reverse pump for the 1988 year serp belt. I believe I may have the right pump. Converting from Carb to TPI I had to have a new end cap on the pass side put on my radiator to accept the Heater core hose. The radiator was rodded so everything there should be good. All I can figure is this. When I turn the key the pump is pumping water from the bottom up. I believe the pump to be the correct one and functioning fine. The engine is freshly rebuilt and was totally hot tanked, All passages should be totally clear. What in the He## is making it run so hot like there is no coolant in the engine. I know the gauge is correct because as it starts to get really hot steam starts to come off the radiator itself. The thermostat opens fine. ????? Things that make you go Humm