I am working with a friend who has a 65 Chevelle with a sb 427 in it and 4:11 gears. The engine dynoed at just over 650 hp. He is concerned about keeping it cool this summer since this is his first big bucks engine. We live in northern california where the temps will reach the hundred teens fairly frequently during the summer. The car does not have a/c. What brand and size radiators have you guys had good luck with?