My car is no monster, but it's a healthy 550-600 hp motor. Ron Davis radiator from T/A, T/A water pump, 180 stat. Proper shroud, 5 blade clutch fan that is properly spaced 1/2 way into the shroud. It gets hot on warm days in traffic. Too hot. And keeps climbing. My thinking is that the coolant is either not staying in the rad long enough, or too long. I'm not wanting to buck up for the electric cooling fan setup from T/A yet, as my current set up should cool this motor. Anyone running a restrictor instead of a stat and what size? Any other input appreciated. Thanks guys!