I recently spoke to a guy from Evans Waterless Coolant at the York Street Rod show a few weeks ago. He said that your cooling system should be geared to your Horsrpower. Up to 300Hp Rad should have two 1" tubes and 300 to 700 HP should have 1 1/4" tubes. I'm going with the Evans that doesn't boil till 375 Deg's. Hope this helps Ron
