Cooling issues 69 RR 440 at wits end!

[themechanic]

Here's out driving at 33C, 40C with the humidex. Generally damn near 100% humidity up here in the summer, we are on the great lakes. This isn't Antarctica! NO puke... tune it, time it properly and drive! OH, that's 104F BTW...
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Same here between June and September. Temperature yesterday was 97F, the heat index was 105F.

 

[BruteForce1.]

Had a turbo car that overheated tried everything 4 core radiator, clutch fan, electric fan, water wetter, removing Turbo, finally took heads off took to machine shop everything checked out no cracks or warpage, Heads were port & polished, changed heads engine ran cool never overheated, I think the machine shop removed to much metal causing heat dissipation problems. Car drove me mad couldn’t figure it out, figured something had to be wrong with Cylinder Heads

 

[451Mopar]

When I first got the convertible with a stock (non0numbers matching) 440, it would run fine with no over heating is I drove under 50 MPH, when i tried to drive faster the engine would overheat, and once it overheated, it would not run cool again unless I let it cool down for a day. I tried the usual stuff and no change. The engine had the original steel shim head gaskets and at a point they must have been letting some cylinder pressure into the cooling system which air-locked the system preventing the water from flowing correctly.
Since I built the 505" stroker for the car using a correct date code block, I just replaced the old engine, and the new engine didn't have the overheating problem.
The engine removed was sold, so I never could confirm for sure if new head gaskets would have fixed it, but I an pretty sure that was the problem on that engine.
As you mentioned, it drove ne crazy, tried different radiators, fans, shroud/no shroud, thermostats, hoses, water pumps and such with nothing making a difference.

 

[Geoff 2]

You can get some really 'odd' cooling problems. When I put a 440 in my 1970 Dart, I could not get the correct top rad hose for it. Never an option here. So I used a 'universal' corrugated hose. Cooled ok just cruising, If rpm went to 6000, temp would increase until coolant boiled. To avoid boiling, had to turn engine off & completely cool down. Eventually found a top hose that fitted ok. No more boiling & nothing else was changed. I suspect the internal corrugations of the top hose were aerating the coolant...& air is a poor heat conductor.