Okay so heres the situation, Ive got a rebuilt 351C .30 overbore. That is getting hot at idle after being ran for awhile or after it is shut off. I replaced the thermostat 180 fail safe, cap, hoses, and even have water wetter in with the 50/50 mix. It doesnt have a fan shroud which I plan to fix but that wouldnt solve the problem after its shut off. Any thoughts? Is it possible my radiator in my 73 isnt enough? Should I go with an aluminum one? why does it primarily get hot after I shut it off, I mean I know its a lack of air flowing and the waterpump not flowing after its shut down... any suggestions or input would be great.