I have a 31' Coachmen Freelander. It has one slide on the driver's side. I purchased 6 LT225/75R16 Goodyear 947 RSS load range E tires three years ago and have been really happy with them. In Oct...
Toyo (and probably others) make a 235/85R16 LR E that's rated for 3042 lbs @80psi. It would make the front end sit 1" higher than the 225/75R16's and shouldn't be an issue for your rims. If your buying tires anyway then I would get tires with a higher rating no matter how well the old ones did. I would never purposely overload a tire. Just one idea.
Scott
EDIT: just checked and the Ribs come in the same size and rating as the Toyo's.