I just today had 285 75 16 Pro Comp AT's put on my 06 2500 hd Duramax 4x they fit with out cranking the T bars. They are very smooth with a nice ride. And they look great. They are a D rated tire but the rated pounds exceed the stock tires by quite ab it they are just an 8 ply instead of 10. A question I have for you Chevy "nuts" what do I have a lly or lbz how do I know? I apologize for over asking this if I have. Thanks,

By the VIN#. I believe it's the 8th digit in the VIN. If it's a D, then it's an LBZ

Thanks, it is a d

Cool. The LMM's are a 6 and I don't know what the LLY's are.