I will back up what Freak and 1200GXman said, with astock A12 newly rebuilt engine and new radiator, as soon as we went above 4000 RPM's the car ran hot...............just shy of the hot mark. Even in bumper to bumper traffic with 110 dergree Vegas heat it was fine............get on the freeway and within 1/4 mile the temp would spike. Intially we used a B210 / 120Y radiator and that helped...........the 3 core GX radiator solved it for good. Even at the track when it's 106+ and me buzzzing the engine to 8K it still stays between 180-200 degrees.

Tom