mini tub
If you just tubbed it I would get some measurements to make sure a frame rail wasn't off 1/4" from the factory. That said, in a perfect world on a Duster you should have 15-1/16" clearance. I would trim your fender lips back slowly with a grinder and a flapper wheel about 1/2", it's a little pointless unless you reverse tub the outer wheel housing shape. You could run 18" DIA on the front and step up to 19" DIA in the rear to use 355/30/19. If you can find them there are 375/30/19 tires out there that will fit. As far as what back space you need on you rims, I would just measure what you got for a rear end. It's not that complicated, and give yourself a secure piece of mind.
You will be looking at a 12"-13" wide rim with a 355/30/19...
If you just tubbed it I would get some measurements to make sure a frame rail wasn't off 1/4" from the factory. That said, in a perfect world on a Duster you should have 15-1/16" clearance. I would trim your fender lips back slowly with a grinder and a flapper wheel about 1/2", it's a little pointless unless you reverse tub the outer wheel housing shape. You could run 18" DIA on the front and step up to 19" DIA in the rear to use 355/30/19. If you can find them there are 375/30/19 tires out there that will fit. As far as what back space you need on you rims, I would just measure what you got for a rear end. It's not that complicated, and give yourself a secure piece of mind.
You will be looking at a 12"-13" wide rim with a 355/30/19...