tire replacement on 2008 Ford F-350 Super Duty

what do i have to do if i want to change my tire and rim size ?

Asked by for the 2008 Ford F-350 Super Duty
Be very very very cautious. This truck has processors that are very picky about your tire and wheel size.

When you change your tires and wheels, you also need to set the correct parameters in the appropriate control modules (ABS, TCM). If what you install does not come close to available ranges of tire outside diameter, you will have an ongoing anti lock brake system issue and a transmission shifting issue.

Believe me; I operated a Ford service department that handled a ton of modified trucks. It's not a good scene. Especially AFTER making the investment and finding out you can't operate the truck properly.
1 more answer
if you want to go with a bigger rim, just make sure that the tires you purchase are close to the correct overall diameter, and that they will handle the weight of the truck.