The factory fan, and cooling system, on your Ram was tested carrying its rated towing-load, up-hill, in Arizona, at their proving grounds. Unless it is broken, I promise that it will be more than enough to meet your cooling needs. "More" blades is not always better. So much more goes into it then that. The shape of the factory "fan-shroud" itself is a science. I am on many other Mopar-based "Hot-Rod" forums where I see people spend thousands on "Custom aluminum radiators", electric-fans with "magic" blades. Most of them have overheating issues due to a bad, or NO fan shroud. The 1970 Plymouth Fury wagon with a 440 was designed to tow a trailer through the hills. Yet people dicked with it, and couldn't make a street-Charger run without over-heating. The Mopar fan-clutch is actually one of the most reliable on the market.