As has already been stated, you DO NOT "need" a radiator in the Altered Coupe/Sedan Class... you must, however, give serious thought to the alternate methods of keeping your engine heat under control. Our car, with a 1000hp BBC engine, a 30 gallon water tank and 100lbs of ice in the water, will, at the end of a 5 mile run, have melted ALL of the ice and the water will be at the 180 degree mark.... which is pretty good, actually....And we use a thermostat so that we can heat the engine properly at the starting line.... We also utilized the same design concept in our lakester when we built it.... and it too works pretty good.