Let’s start with the basics…do you have your radiator support to hood seal in place? How about the lower splash pan to radiator support seal? And of course the hood to cowl seal? Without these seals in place, air can simply flow around the radiator instead of through it, it’s like sucking through a straw with a hole in it. The idea is to trap air in front of the radiator, the use a conical shaped shroud on the engine side with a clutch fan at least 1/3 of the way into the fan opening. This will create a vacuum on the radiator and pull the air through from the front. It all acts like a funnel, straightening the air and drawing it through. A pusher fan will effectively block this flow, like when you dump all the liquid into the funnel at once, as opposed to swirling the funnel a little bit and allowing the vacuum effect to do it’s job.
Now, if you are running a 440/6, you need to be running a 26” radiator, a 195 thermostat, factory shroud, clutch fan, and have all the seals in place. This will give you the best airflow, and keep the coolant in the radiator longer, and have the most radiator surface to help cool the coolant. Don’t fall for the notion that a “160 thermostat keeps the car running cooler” BS, that’s not true at all. A big block Mopar likes to run hot, and 195-210 is right in its wheelhouse. To me, you are throwing parts in your way of progress trying to push and pull air through a 22” radiator for a 6bbl application.