Opinions from 4x4 dually owners on tires

I have the exact same truck you have, but with stock-sized tires. I have BFG All Terrains. But I have to say, I'm a bit confused -- you say yours has 315s? If I read that right, that's just over-the-top wide for no other reason than bling. Previous owner apparently wanted the world to know he had a dually.

You can go a little wider tire than stock, but too much becomes a problem.... Parking spaces, narrow roads, etc.

I'm not real versed on rim sizes but they say Ford 16-6K rear. I'm assuming that is stock and I have no idea why he would want that wide a tire. I took pictures of the tires and put an ad on craigslist to see if I can find a buyer after I swap them out. Thanks for the input. Boatycall - That's quite the set up you've got.

I agree with Boatycall. Previous owner was probably just interested in drawing attention to his fat butt by making his fat butt fatter ... er ... his truck's fat butt. I'd take it back to stock tires as I see no practical advantage to the wider tires. Stock tires will have plenty of capacity for your camper, will better accommodate standard swingout brackets, and keep your overall width down. If you have to buy new stock rims you should be able to recoup some if not all of the expense by selling the 315 tires and rims as I'm sure the nonstick items weren't cheap! If narrowing your rig even further is desired then super singles would be an option but they won't be cheap either.

If they say ford on them, then they are narrow wheels. 315s are just a bad idea all around on OE wheels! If they're not wore out in the center from being stuck on those rims then they're worth some good bucks.
Just a suggestion, but if you're selling them on CL, get them off your truck and ready to go. I buy CL stuff all the time and wouldn't want to wait on you going to the tire shop. If they're desirable tires they'll go quick and the buyer will want to flip you some cash and drive away, not dink around waiting for you to get your tires swapped next Tuesday.

If you go to Americas - discount tire you my not be able to buy anything that is not rated for the 6" wide rim , choice may only be stock tires
I put 255/80/17`s on my truck at Americas a few years ago that say for 7-8.5 rims on my 6" wide , they never said anything , went to get tire a month ago and I was told they can only put 235/80/17 - stock ,on because of rim rating
Most all dually rims are 6" wide , a few aftermarket are 6.5" , you have to go to 19.5 and 20`s to get taller tires , still narrow though
My experience with wider tires on narrow rims = low mileage , they wear out fast

Thanks for all the opinions. I ended up getting stock (235/85R16) Yokohama YK-HTX today. I was going to go with BFG A/T's but was talked out of them because I drive freeway and only camp in campgrounds. Made sense and when we retire in five years and head up to Alaska I can always go for an all terrain tire. About an hour after I got back I sold the 315's to a great guy off of craigslist which paid for 3/4's of the bill. ?? On top of that my swingout brackets came in so the camper will be on the truck this weekend. It was a good day.??