Sounds like the same issues I chanced. Fought overheating for YEARS. Three radiators, host of waterpumps, fan clutches, headgasket, all the stuff you changed and some more yet. The more I increased the flow (waterpump, high flow thermostat, etc) it just made matters worse, not better.
Scoring the IR gun is a good idea. Helped me. Restricting waterflow almost helped. What solved it was getting a 97+ fan from the boneyard, hooking up a rely and a switch and letting it run all the time. Simple test... unplug the a/c compressor and turn the a/c on. This will force the fan to run w/o the heat input of the a/c unit.
Seamed my issue was a thermal capacity issue. Once it overheated, I couldn't shake the heat. But with the 97+ fan running all the time, it don't overheat and can keep up with demand.
I did have to give up turning on the a/c on the trail, but I made the doors removable so it's not too bad. After a couple hard hill climbs I may have to turn on the heater to shake off some heat, but it only takes a couple minutes to get it back under control.
Scoring the IR gun is a good idea. Helped me. Restricting waterflow almost helped. What solved it was getting a 97+ fan from the boneyard, hooking up a rely and a switch and letting it run all the time. Simple test... unplug the a/c compressor and turn the a/c on. This will force the fan to run w/o the heat input of the a/c unit.
Seamed my issue was a thermal capacity issue. Once it overheated, I couldn't shake the heat. But with the 97+ fan running all the time, it don't overheat and can keep up with demand.
I did have to give up turning on the a/c on the trail, but I made the doors removable so it's not too bad. After a couple hard hill climbs I may have to turn on the heater to shake off some heat, but it only takes a couple minutes to get it back under control.