vanbikehorse wrote:

7" rim width is the minimum manufacturers spec for 265x75x16 tires. The stock rims are weight rated to match the stock tires. All that notwithstanding, the 265's will certainly fit and work on the 6.5' rims. Your tire rim combo won't be rated as high as the tires indicate. Likely as not the rims will be strong enough for the tires even though they are rated less. The choice is yours depending on what you are trying to achieve.

I went for the bigger rims that were rated at 3800 lbs each to exceed the tire manufacturers spec. My Chevy dealer could program my anti-lock brakes for the new tire size as that was a separate module from the engine module. He could not program the speedo as there was no 2500HD with those size tires, so I did it with my Hypertech.