Tire size confusion.

[Grit dog]

^Of course in only the context of the OPs truck and question, the pizza cutter sizes he needs I believe are only made it LT D or E load ratings. However any dually that isn’t hauling serious weight, the rating of the rear tires is of little concern. Even some wimpy tires in the low 100s load index is more than enough when x4 in the rear. The Front even on an old dually gasser would be within limits with low 100s load rating.
This is important if getting a size like 245-75s which I believe have LR C or XL as well as D/E tires available. To make sure you get what you want.
This is not a blanket fits all type of selection but easy to figure out what you need.

 

[Dooley]

I believe it's @Dooley that runs the 255/85 on his trucks and it looks/works well. Maybe I'm remembering wrong though.

My radial equipped dullies came with the optional 235/85-16.
At first opportunity I replaced them with the 255's.
Never had a tire rub with vehicle or dually rears.
The 215/85's were mostly found on base line ordered trucks.
My earliest duallies I ordered came with 7.50/16's as I ordered.
The middle years came with L78/16's bias ply.
It would be neat if I could have kept all of them.

You must be registered for see images attach

 

[JBswth]

My 84 came with 235 85R16's on it yet I find vendors telling me they won't sell me them that it's supposed to have the 215 85R16. My door placard says otherwise(235 85R16)

That is weird. Normally they will sell you anything you want. But then I remember when they would put an inner tube in a tubeless tire that didn't hold air very well. Now, supposedly, most will refuse to unless you are friends with them.

J. B.