[ensclark]

Your stock tires are 32.6 inches tall. The with the 17 you could go with the stock size that comes with it 285/70/17. These are 32.7 inches tall. To keep it in the "stock" set up for what the trucks computer is programed for you should stay close to this range. Even if you were to go with 295/70/17 (33.3 inches) the only difference I know of is that at 60 mph you going to actualy be going 62mph but then again how many of us get our speedo's calabrated, they all could be off a little. On invalidating the warranty, I don't see how changing your tires would put it out of spec for the warranty. If you did change them out with stock 17s I don't think they would even know you changed them, and I don't think the rims are covered. The only thing that a mod does is not cover the mod under the warranty. They have to prove that what you changed is the cause of the problem. Can't say that your lights don't work because you changed the tires. I'm sure a lot of us would be in trouble if this was the case.
my .02
I hope this helps, I'm sure that there are others with ideas on it too.