285's on stock wheels, should be able to clear without doing anything. If they rub at all, you can simply turn the stock keys, lift the front end up to level with the rear. Measure the fender heights after driving it around the block, adjust as necessary to get the left and right side as equal as you can, and as close to the same as the rear. You may be close to maxing them out (at about 1 1/2"), but you won't have any problems anywhere with clearance. Some say that 305/70's will also fit (about 3/4" wider than the 285's).
Then get an alignment. Your tires will thank you.