I recently purchased tires on Ebay. i went to have them mounted and place says they are 6 ply and I need 10 ply. They were the right size. I have a Duramax 2002 crew cab 4X4. They will only mount them if I remove the wheels and bring them in. I don't think the company will take them back and give me 10 ply. I wrote them before i bought them and they said same size go ahead and use them. I don't haul anything with this truck so it's not a hauling issue. What do you think