Brief history, don't remember why but replaced the thermostat a few years ago, during installation of new one I pinched the sender wire between the housing and the block. Since then the gauge has never come up but about 1/4 over C. Figured the pinch affected the resistance of the wire so wasn't really worried, drove great, had good heat, gauge stayed consistent.
took the truck down to the coast for a job and ended up leaving it there for a few months. When I went back to get it, I had it idling, using a mobile air compressor to air up a tire, and it blew the top hose. Now it was 100+ degrees in the direct sun. So, had to leave it another few months. Filled it back up and this time I fired it up and the gauge spiked before I got out of the driveway, top hose was rock hard. Figured maybe the thermostat was stuck so yanked that and put the hose back. Filled it up to the top of the radiator while running and filled to the line on the overflow. It does seem to be cycling through the overflow, both the top and bottom hoses have pressure, but I have weak heat and the gauge barely registers. It also has a stumble and slight tic that it did not have before. I've run plenty of vehicles without thermostats here in SC, I've never had a issue like this before.

My guesses would be water pump or a clog in the system itself.

Any ideas? Thanks in advance!

 

I believe you need to replace the thermostat. I'd flush cooling system and check the clutch fan.