Cooling issues, could use some advice

I'm not a fan of flex fans. I would trash that and go with a good old 7 blade fan.

Next, you have to make sure that the airflow is going THROUGH the radiator and not AROUND it.

There are a few things that you can do to help this:

1. Get a good fan shroud. The shroud is important to help the fan pull the air through the radiator fins.

2. There is a critical spec that they use to measure the amount of "overlap" between the fan and shroud when they design cooling systems. It's acronym is FOOS (no, not Chip Foose), it stands for "Fan Out Of Shroud". Like I first said, it is how much of the fan is overlapping with the shroud. A good starting point is 50%. Which means half of the depth of fan is covered by the shroud.

3. Next make sure that there are no gaps for the air to go AROUND the fan and/or shroud. check for gaps between the fan and shroud, and gaps between the radiator and front mounting wall. If there are, fill them with foam, or flat rubber "sheets" so as to cover the gaps and prevent any air from going AROUND the radiator and shroud and direct it THROUGH the radiator and shroud. The radiator will not be able to cool to its full potential if you can't get all of the air to go through it.

Also make sure that you have enough grille area for the radiator. Many grilles can be restrictive. The original Grand Cherokee, had 8 openings in the front grille. They changed that to 7 bigger openings somewhere between 94 and 96, (I can't remember the exact year, but I wanna say 95). The change increased front end air flow by 10% which was needed to help the A/C performance. The original system had almost 425 psi "head pressure" (pressure through the condenser) when the maximum spec was 450 psi. The new grille helped lower the head pressure approximately 25 psi so they weren't running so close to the maximum head pressure.

The new Shelby Mustang GT500 with 662 HP does not have any "webbing" in the grille because they need all of that area for front end cooling, any ribs in the grille will restrict the airflow. They eliminated all of the "webbing/ribs" from the earlier models because they need all of the airflow that they can get. Ford realizes that they will have to eat some warranty for rocks getting through the front end and damaging the cooling fins/tubes on the condenser, but have to do it for proper cooling performance.

I cringe when I see cars driving around where people change the grilles from stock and use aftermarket or block some of the airflow with cardboard etc. If those changes restrict the airflow through the front end and the car/truck overheats, the OEM will not warranty any failures from overheating as they were modified from what was originally designed and proven with testing before ever being released to the public. Part of the testing includes parking the car less than 1 foot from a wall at the Phoenix proving grounds during summer and letting it idle for over an hour while monitoring the temperatures and pressures in the cooling system and A/C system. They also test them while pulling a 5000 lb trailer with the A/C on max through Death Valley where there are signs warning you to turn off your A/C to prevent overheating. This is a very stressful test for your A/C and cooling system.

Good luck, I hope some of this helps you.