Snoking, the axle IS NOT rated for 6084. I don't know where you are getting this information. On the 3rd gens it's basically (except for 1" difference in width) the same as the dually axle. There are no single rear wheel tires that will exceed the capacity of the 11. 5" axle. I don't remember the exact capacity but as I recall it's around 10,000 pounds. The 3rd gen trucks have much stronger axles than the 2nd gen. My Dana 70 on my 2500 2nd gen was rated at 7500 pounds. The door sticker on my '05 says 6300 pounds with 75 pounds of air on my stock 265's.