Right now, I'm sitting here totally pissed off with Rv manufacturers. Last year while driving from the west coast to Toronto and back I had 2 major tire blowouts. This year, I'm planning on a longer t...
Figuring 20 percent pin weight, each of your tires is carrying 3200 pounds.
I also just put on the Sailun 235/80-16 tires for my 14k fiver. Each of them is rated at 4080 pounds at 110 psi. In your situation, I would suggest going with the 235/85-16 Sailuns if you have the clearance - they are .9 inch taller. They are rated at 4400 pounds each.
The 85 series tires cost only a little more then the 80 series.