Does the 1500 come with Load E tires?
If you know your axle loads, I've seen inflation tables of load vs. pressure - though I can't seem to find it now.
Otherwise, I try to make sure even contact across the tread. Chalk sometimes helps.
For my TV, I generally run the fronts at 70 loaded/unloaded and backs at 60 unloaded/70 loaded. Otherwise I would bounce down the road. Now when I had the TC or a load of stone, the backs would be at 80, but I would be at max payload then.
2006 F350 6.0 CCLB SRW
1999 Lance Lite 915 - Sold