If the fan is more than a couple of inches away from the radiator, you need a shroud. If the fan isn't approximately centered on the radiator core, you need to reposition the radiator, or find one that's a better fit. fabricating an appropriate shroud isn't difficult for anyone with some basic sheet metal skills. Just be sure that no more than half the depth of the fan blade is inside the shroud. You also need to remember that the MINUMUM temperature of the coolant is established by the thermostat. If the coolant is trying to boil with the right pressure cap for the cooling system installed, you need a bigger radiator. If the coolant isn't boiling, the engine isn't overheating.
Jerry
