Over heating in traffic or while driving? Do you have a vac adv can and is it on ported or full manifold vac? If it's on ported, try swapping to full manifold. More advance will help it run cooler at idle. You could try richening up the idle on the carb as well. Did you "burp" the radiator after the rebuild? I'm having same issue, but I think on mine it's the fan.
