What's the biggest tire you can safely run on a dually?

[GTODually]

My tires are shot, I have lt225/75r16 however they seem small? Is this correct or can I go bigger?

 

[skylark]

I have 235/85/16 on the back and 265/75/16 on the front. They are the same height as each other.

 

[GTODually]

Ok thanks!! No trouble under load or hauling?

 

[Kyle97GMC]

There is a guy here that is running 35" swampers on a lifted F350 dually. Why? I have no idea but it looks awesome hahaha

 

[skylark]

No issues. No spacers in the rear either. It did rub slightly on a bump at full lock but once I replaced the ball joints the rub stopped.