The impossible to solve overheating problem

the rad hose off test isnt really the best test.
Depending how you were adding water to the system the flow from the hose would taint the results.

If it overheats again, place your and over engine in front of carb to feel the wind blowing through rad. Firstly, it better be a good draft and it better be hot.

Friend with his chevy dropped by yesterday, looking for a vacuum advance. His one year old chinesium one quit,i had a working 40 year old one. It started overheating. Vac advance repair cured it.