I have a flathead that runs hot in about 5-6 laps, it gets up to 480, its a SA flathead, It is 80 over, 4.500 rod, stock crank, I run the cyclone carb, the flywheel is a clements small flywheel with the fins at 34* timing, I went down with timing and it didn't help, its a stock head that's been cut for SA with a fire slot and it has stock valves with the 112alt cam.