I have gotten a chemical test and a pressure test changed out the thermostat and checked the water pump but still I am over heating any other suggestion

 

What is overheating for you ? What coolant temperature are you running ? What is your ambient temperature ?
If were you, I would eliminate completely the thermostat and its bypass hoses to diagnose, then re-measure coolant temperature.

 

I ordered a temp gun the gauge has quit working altogether but it's getting really hot and the under hose of the thermostat is cold

 

@Maxwell_land this not rocket science, it is the same as every other vehicle:

• Rad
• water pump,
• thermostat

But you can do nothing without knowing the temps, start simple :

• Get a eml327 bluetooth OBD from amazon a25-50 will do - if you have an Iphone make sure it is compatible
• Get torque for your phone
• Set it up
• Start your truck and let it get to full operating temp 188-212 depending on thermostat for about 10 minutes
• give it a few revs
• shutdown
• Check hoses

Now you can diagnose

 

Get an inline thermostat. Remove the thermostat element completely. Loosen the radiator cap one full turn from full tight. If it still overheats you have a plugged radiator. Even a truck with a blown headgasket will not overheat if there is coolant in it and no thermostat in the housing.