One of the best things you can do for cooling, is to have an unsealed engine compartment, so the air will pass
through the radiator easier. Hood vents help. Also, don't seal off the back of the radiator around the fan. That way when you are going down the road, your engine cools without even having to turn on the fan. A fan shroud is helpful, but a more open one, like a stock Mopar.
Also, an unsealed engine compartment helps the front of the car not be a big air brake. Racers use to lift the back of the hood about 2 inches, to vent all the air in the engine compartment, and increase their 1/4 mile times by .2 or .3 secs.
Also, took a 6" by 5 ft piece of sheetmetal, attached it to lower front valance, painted it black, and it made a great spoiler. Not only does it reduce under car air drag, but creates more of a vacuum in the eng compartment so your radiator cools better. Also, with it, at 90+ mph, the front end stays stable, and the car doesn't want to take off like a plane, or get all squirely!