Based on the OPs 7.3L history, none of this is new to him probably, but I thought I'd share what I'm doing to get my bus in shape and keep it running well.
In general, what I like to do is do a solid job of cleaning all the built up crud, oil, etc. off so I can see the zerk fittings, watch for where anything might be leaking, etc.
Then I like to inspect and make sure things are secured, zip tied, etc.
I have taken things one step at a time, for the most part, and repaired or replaced as needed. I didn't start out this way, but I've learned.
Per fluids and filters, the general gist I get from what I've read on here is a decent fluid + a decent filter changed more frequently than not will provide the best overall protecting your drive train.
I used the following:
Shell Rotella 15w-40
Valvoline full synthetic ATF (they claim it's transynd equivalent, but don't want to pay to have it certified)
I initially used Power Service fuel additive, but after watching a great YouTube comparison of like products, I am switching to HotShot. A friend switched from Power Service to HotShot after I told him about the video, and said he was amazed how his Cummins 5.9 24v ran with the HotShot.
Oh, one problem he's had with his Cummins is if any air gets in the fuel line, it locks up his injector pump and no start. The first time he did this, he didn't pay attention to it and it appears cavitation ate the pump. He has a new pump, but it happened again. He suspects his fuel gauge is off a bit and he runs the fuel level too low. He's now going to keep it at a 1/4 tank or more to avoid wrecking another injector pump.
I've added a Griffin cooler, https://www.griffinrad.com/OffRoad/coolers.php
(the larger one), for my tranny, but have yet to hook up the new hoses. s2Mikon turned me onto his setup and I flagrantly copied it. 1.75" tube and 1600+cfm fan with a 200F on / 185F off thermo switch.
I'm just about to dig into my cooling system. My engine uses good ol' green antifreeze. I'll use pre-charged with a DCA pellet coolant screw on filter (T444E and cavitation prevention).
I've got a viscous clutch fan (I think), that appears to be in good condition, but honestly, I'm not sure. With a hard pull, it spins exactly 5 times, so it seems okay. But, the whole fan activation system is suspect. I don't hear the fan "roar" that others speak of and my coolant temp is always right about 210F, which is well within operating range...but??
So, I'm pulling the radiator, all hoses, thermostat (depending on how things look....maybe the water pump) and upon recommendation, the accessory pulleys. I'll test them and see.
New hoses, thermostat, power wash the radiator and charge cooler, determine what kind of internal treatment they may need.
I also am wondering what kind of shape my bi-metal thermo coil is in. I don't know if it's filthy, broken, adjusted properly (if it can be adjusted), etc..
I've read up on the Horton electromagnetic fans, but I'm not sure I need to go there.
The main issue I have with my coolant system is my top radiator hose always collapses during cool down. All I have to do is release the vacuum via the coolant tank cap, but I need to determine why it's not releasing the vacuum automatically. A new Motorcraft 10psi cap didn't help.
I figure the more I run it on the cooler side of the operating ranges, keep the fluids viscous, the filters clean and levels good....I'm doing the best I can.