With the leveling kit you can run 37 x 13.50 18 with the right rim. Not sure if it will work with the stock ones. In the winter I have 35 x 12.50's 18 I put on my stock rims with studded tires. I only went with a smaller tire because I haul a camper and trailer that may rub my fender flares with the 37's on a good bump due to the weight. Without the flares I would not have worried about it. There was plenty of room.
I am running a stock 20" wheel with Nitto 325-60-20 which is equal to 35"x13.50"x20". I have a ready lift 2" leveling kit and the tires have no rubbing at all, even at full lock and going on alternating terrain. I reccomend this size tire because it will not leave you wanting more. It is the perfect size for the aggresive stance, but not looking like you shoe horned too much rubber under the wheel wells. Good Luck!!
35's looked like they were too small on the truck. I actually had them go back and forth two or three times between the two tire sizes. 35's probably look fine on a truck without aftermarket fender flares but I have 18's instead of 20's as well.
I just put 35x12.5x20's pro comp extreme all terrains on my 08 HD CC 4x4 with facory HD wheels. In spite of what most tires shops told me (Tire Rack, 4wheelparts, NTB), they fit pefectly, no rubbing, and fill the wheel well much better. I too did not want to put a lift on my truck as I had on previous Fords. Forget the leveling kit, you don't need one to run 35's.
thanks guys and yes i do want to keep my stock 20's but im debating on the 35's with no leveling kit or 37's with a 2.5 leveling kit and upgrading my shocks all the way around and maybe putting in the f350 blocks in the rear for extra hieght i like the nose high look just a little bit but not to high in the front
ok finally got the 2.5 leveling kit with new rancho rs9000xl shocks and running a set of 37x12.50x20 nitto trail grapplers now got a major swaying prob in the rear end any body no how to fix that or whats causing it thanks there on the stock 20x8 hd wheels
The tire you got is most likely a load range D rather than E, therefore the sidewall strength of the tire is less. Also the max PSI should be around 50 cold. Combine those two factors and 37" of ride height and your gonna get a squirmy back end.
no surprisingly there an E and the other prob with the tire pressure is the TPMS keeps going off I got them down to 60 im trying to go lower a little at a time thanks ille get some pics up once i figure out how to lol