In Reply to: 8N V8 conversion posted by jeff walker on August 31, 2018 at 20:06:20:
The Ford flathead V8s were notorious for overheating. There were issues with the water pumps that are best solved by using the modern pumps with better impellers and bearings from Mac's Auto Parts or Speedway Motors and others.
How is the plumbing hooked up? Engine with two inlets and two outlets. Radiator with one inlet and outlet. Plumbing may be causing problems with flow. There was no mention of thermostats. If there is no thermostat or other restriction, water may flow thru the radiator too fast to get much benefit from the fan.
The 8N radiator has plenty of capacity for the original 4 cylinder, but seems small for the Flathead V8. I did not consider using the 8N radiator was an option. I bought a new radiator that was built specifically for the flathead V8.