Originally Posted by TimBrown
What is the back spacing on the stock wheels?
Most stock wheels have 5.5" of backspacing with the only exception being Moabs (5") and Gamblers (5.25").
You could run up to 4.75" of backspacing and have enough room for 12" wide tires. You would rub slightly when turning full lock. If your axle is not centered, the rubbing will be worse in one direction.
The size of the side lugs on the tire is a factor in how much it will rub.
What type of lower control arms is another factor (many aftermarket arms give you a little more tire clearance).
If you want full turning radius lock to lock, I think 1" or 1.25" should be plenty for you.