@Randy88FJ62 @RodrigzCrzr
I did have some gremlins at the very start of the trip, which made zero sense to me ( since it was 12am and it was in the 50's outside).
The gas gauge did not drop to zero, it actually went to over 100% - which was weird since I was about 75 miles into the trip. Most of the time it took until about 50- 85 miles before the gauge started to drop below Full.
But after the initial drive the gauge started to act normal. That said, I didn't get any overheating spikes on the drive down to the desert, except in one place - which was climbing out of Bakersfield on the way up to the summit of Tehachapi on Route 58. Summit is around 4,037ft.
Most of the time if there was any significant grade, I would throw on my flashers, drive in the slow lane and ascend most hills in the 50mph range ( until I ran out of juice and would get into the 30mph). If I tried to push it the temperature would spike and I would pull over, turn off the truck for a minute and the gauge would be back down to 1/3 level. Basically I drove with the temperature gauge at the 1/3 level for 1,000 miles of the trip. If it started to creep up to the middle tick its hard for me to tell if it will jump up to the 3rd tick(red zone). So I try usually to keep it at the bottom tick, which appears to be the normal operating temperature for the engine.
I have a standard 3FE, nothing special. No add-ons. I've thought about changing the CST to 30k or 50k. I replaced my original fan clutch with an Aisin FCT-017 back in September.
Also replaced the Water Pump with an Aisin at the same time as I redid the CSF 2708 radiator. New thermostat OEM, new heater hoses...