Yeah man. Its air flow. I dont even know the guy, but I know his stroker screw/roots combo will take his engine water temp up to operating temp within two blocks from stone cold. When you make 800 hp, you make way more everywhere. Good points were brought up about water pump rpm, but I have seen this many times. When you get into big power there are coolers everywhere, and they often require factory air deflector mods, and of course extrA coolers. Thermal run away is real. You get on the wrong side of your thermostat with 750 foot pounds and 500 hp at 2500 loaded and once it hits its limit, it goes nuclear.