Hot at highway speeds

$1,400 radiator? Whoah! I'd run a full fan shroud. I was told that at higher speeds, there is a tendency for air to stagnate at the front of a cars radiator as the fan cant pull it through fast enough. (look at a Daytona/Superbirds small inlet in front) a fan shroud is supposed to assist in this (could be BS but Ill pass it along for you to decide) try a teaspoon of Calgon dishwasher detergent in the radiator, it acts as a wetting agent, making it have more contact area with the cylinders. 210 is nothing for a motor.