I have a sbc 350 in my jeep with a 4 core new radiator. The engine gets hot when driving on the freeway over 20 miles in distance, while four wheeling in the desert it doesn't. Don't understand what is happening or why? I have a 15" electric fan and shroud on it also.
Are you running a thermostat?
If the fan is behind the rad is it a puller fan?
Start it up get it warmed up fully. Pop the hood and hit the linkage to quickly rev the engine up a few times. Watch the lower rad hose. Make sure it is not collapsing.
Do you know what was good about the good old days? I wasn't good, And I wasn't old!
Senators and Congressman should wear uniforms like NASCAR drivers so we could identify their corporate sponsors....