408 cooling issues

Is it staying at 190 or going past that and not cooling down? Is your EFI controlling all timing? Can you monitor AFR?

My dad tried dual fans on his Coronet with a 440 and Champion radiator and it would overheat. It actually ran cooler with no fans at all than with dual 12" fans. He put a Flex fan on and has been happy ever since, but other issues can cause overheating.