One of the biggest hang ups in stepping up the tire size is suspension and steering contact. Here, we see that going from 31s to 35s with the stock backspacing would place the edge of the new tires right into the spring hard. To compensate for this much tire with this narrow axle, we'd need to decrease the rim backspacing by at least 1.5 inches to move the edge of the tire away. However, doing so would then place the outside of the tire in contact with the fender. The solution is more lift, some sheetmetal cutting, or a slightly smaller tire.