66 V6 not boiling - sucking air?

I throught I had a boiling problem with my Dauntless. There are heavy bubbles that I can feel and hear in the upper radiator hose and heater hose.
I'm stuck - can't figure out what to do next.

- Thought it was an air bubble: Removed the T'stat and ran it. Water is flowing now and there is no air bubble.

- Its 110-120 degrees with the t'stat out and I can feel and see the air getting pushed up the upper radiator hose (it is not overheating like I thought). Once the engine gets up to that temp, Coolant really starts to puke out of the overflow (or if I leave the cap off It pukes out the rad fill).

- There seems to be a lot of air getting into the the cooling system and working its way through then coming out the top as a big puke.
The coolant seems to be getting airated too.

- The engine runs great, starts easy, is not sending coolant smell out the exhaust, does not show milkshake water in oil.

I have changed all hoses, thermostat (before I took it out), belt, boiled and pressure checked radiator and heater core, tried new caps.

How is air getting into this thing? Or if its not air, any idea what is going on?. Head gaskets? cracks?

Any tests that I can run?

The only part I havnt changed is the water pump and the pump isnt leaking. The jeep has been sitting for 20 years but was well stored. it only has 30k miles on it.

Thanks, Tom

 

Pressure test the cooling system. When it leaks down you'll have to find where the coolant went (if it did). Possible head gasket, compression gasses going into the coolant. But I would test it and not assume anything.

 

they make a funnel that actually screws on as a radiator cap. you use it to catch all the puke and as it runs it settles down and sucks it back in. Not sure where youd buy one but thats what they use at my brothers shop.

 

Thanks
will do a leak down test. The more I think this through the more it points to head or intake gaskets.

I should have stuck with the 4 cylinder Jeeps.

Tom