Glad it worked out, I have no idea of your abilities so my methods might not make sense to you .
Unless your truck is overheating and spewing clouds of steam do not replace the thermostat with a lower rated one ! .
Gasoline engines run best at close to boiling temperature, this is why they have pressure caps ~ every pound of pressure raises the boiling point of plain water by 3 degrees, adding properly mixed (60% coolant 40% distilled water, NEVER use tap water) coolant raises the boiling point as well as preventing corrosion .
I'm amazed (shocked ?) that no one else chimed in on your questions .
I'm an elderly retired Journeyman Mechanic who's extremely well covered in all the basics of running a classic so ask away if you dare trust my foggy memory .
BTW ~ as you can tell by my signature, my name is Nate .
