I can agree with BenK above except for the last line: "If not, then use the chalk or masking tape method to determine the proper PSI for 'that' loading during that test"
Bad advice, tire manufacturers have load tables for this exact reason. Using an arbitrary method to determine something as important as tire pressures is asking for trouble.
Your door sticker is no longer relevant.
Call your tire shop and ask for the weighting scale for your tire. You'll have to weigh your rig fully loaded and then you can adjust your psi to the actual load.
That will be an extremely rough ride if you put 80 psi in them, besides being completely overkill for any load you will be putting on them.
I've been fighting rough ride for years now, previously on a 2005 ext cab Chevrolet 2500 and now a bit with my new rig below. The previous truck bucked badly on segmented highways when towing a TT.
Turns out I was running WAY too high of pressure with my tires. I consistently ran 75-80 psi which caused an awful ride. Now my pressures are set to the actual weight on the tires, not what the door placard says, this is especially true with aftermarket tires. I run 45 front, 35 rear when unloaded and 45 front, 55 rear when loaded.
These numbers came from my tire manufacturer according to their load tables.
Weigh your rig fully loaded, call your tire manufacturer for their recommended pressure.
Something to try.