[JellyBeanDriver]

Originally Posted by RT Big Block

Have you check the lower radiator hose ? It might be sucking itself shut. The wire goes bad in them sometimes .

I have not seen wire in the lower radiator hose for 30 years. Read something about them not being needed except at the factory when they would pull a vacuum before filling a system with coolant just to prevent air pockets. After this they're not needed.