I had a problem some years back on a rebuilt engine. Seems that when they rebuilt the long block they didn't bother to drill out and pull the freeze plugs, they just knocked them into the block. They forgot to fish one out! Blocked coolant flow to the right side of block.

I don't know when the radiator on yours was rebuilt. I have had a radiator flow test fine with a garden hose, bunches of water gushing through with hose in filler neck & rag stuffed to increase pressure sealing. Turned out the radiator was about 50%, one half was almost completely blocked. Had it rodded out, good to go.

You might study up on 350's, see if they are prone to air traps in the block. Many engines have to be burped, or you have to drill a 3/16" hole in thermostat base plate to bleed air out of block. Air pockets prevent coolant flow.

Wrong heads and or intake manifold on the engine could have coolant passages choked closed? Wrong head or manifold gaskets can do the same.

Check lower hose on radiator, that it has a strong spring on it, so it doesn't collapse & cause loss of flow of return coolant. Run it hot, leave it runnning & pop the hood & check?

Possible reverse rotation water pump? Wrong water pump for coolant passages in block? Wrong water pump gasket?



Edited 1 time(s). Last edit at 07/14/2009 10:55PM by JimmieD.