'95 F-250 came with size LT235/85R16E ties. By far the best tire of that size for that truck is the Michelin XPS. But it's also very expensive. I wore out two sets of XPS tires on my '99.5 F-250, and they lasted about twice as long as the BFGoodrich AllTerrain, Cooper Discoverer, and General Grabbber tires I tried before finally giving up and paying the big bucks for the XPS.
The XPS comes in either highway rib or traction tread. Here's the traction tread for the rear axle in most parts of the country with either mud or snow worries:
I live in the desert, with neither mud nor snow worries, so I had ribs all around. Loved them.
And yes, you will be severely overloaded over the GVWR of your F-250 with any 40-foot toyhauler.