I have a 2008 Silverado Vortec Max Extended Cab with the Trailer Package. I am looking at buying a 5th wheel toy hauler that's about 10400 lbs so I can take my full dress motorcycle to Arizona. I have been told by 2 dealers, both have seen my truck, that I will be fine hauling this rig. One dealer told me over the phone that this would be too much weight for my truck. What is the opinion of the knowledgeable folk out there? One of the guys who saw my truck said I would be fine, as long as I put 6 ply tires on the rear. I went to the dealer that I have bought tires from before and he said not to just put 6 plys on the rear, but, put them all around or else I would wreck my transfer case. Is this the case?