Hello,
I replaced my thermostats with GM factory units and now its running hot.
I installed the thermostat with the small weep holes in the rear position. The taller unit was forward. pointed ends up with the springs lowered into the housing. Used a previously posted diagram for guidance.

Removed and replaced 3 gallons of Dexcool and filled until fluid came out of seep hole.
After driving around last night it never cooled to 180 reading.
Upper hose didn't pressurize as i would have expected.

Checked this morning and the upper radiator hose has completely collapsed.
Pulled cap and the pressure was released.

I have just read about warming it up and revving past 3k a few times.
Will try that today. Assuming I have air in the system?

Thanks