I just had new tires put on my class C. The new tires seam to have a bit more flex on the sidewalls then the old ones. The tires say max pressure 80psi for load range E. But the sticker in side the dr...
Well there won't be any harm in running the fronts at 80. The worst that could happen is that you don't like the resulting ride or handling as much. They do look low in that photo.
As suggested, if you could weigh the rig axle by axle, then look up the weights in a tire inflation load chart, you'd find out what you can/should run in them.