I have been on the discount tire website trying to decide what tires to go with on my 08 F250. I spend a lot of time offrod driving to rig locations in West Tx and my current Cooper Discoverer A/Ts have just about had it. I have had people recommend me Toyo A/T IIs or Nitto Grapplers. My current tire size is 275/65R20s and I was wondering if it is possible to go with a 35x12.5R20. Any help would be great and I am ready to order ASAP