Clean block, actually the cleanest block you can have. Radiator was cleaned and repaired, original.
60/40 antifreeze solution. Engine pans are in place. Have a license plate because it's law.
Running a temperature gauge in the neck.
Have a thermostat with the thermostat knocked out, so a 1 inchish hole to slow the water down. Before knocking the thermostat out, car would overheat on hills easily.
Climbing hills at 7,000+ feet on 100 degree days is tough, to the point of pulling over and waiting.
50mph on 100 degree days is running between 185 and 190. Car is loaded pretty well. When it's 80 degrees out car will run 5-10 degrees cooler.
While this was stationary tests:
https://www.tulsamodelafordclub.com/...-fan-air-flow/
4 blade is significantly more air. There is another article out there from years ago, but the scan is too small to read by Ed Rossig.
If you have a wind perpendicular to or behind the car, the air flow through the radiator might not be the "doesn't matter above 35mph" that you think it is.