If you want maximum cooling you can install a Hayden aftermarket thermal clutch fan. It looks very similar to the original torque fan.
I researched the crap out of Hayden heavy duty thermal clutch fans and found a Cadillac application (Hayden 2731 or 4 Seasons 36999) had the best fit with regard to depth in the shroud on a stock 3 core radiator, cast iron pump in a '69 Dart 340. The "correct" listed fan clutch 2707 and 2747 did not have the correct depth in the shroud.
