Well boss, I just did a couple of tire conversions found via google (my bestest friend
) and a 315/75/R16 sits at a diameter between 34 and 35".
That said, I had 35" on my truck with a 6" lift, and had rubbing issues that required lots of trimm. I know LA had a 3" body lift on his truck with 35's and had major rubbing issues too.
I'm not sure how high you have things cranked, being a 2500 and it's all 1500 that I've seen/dealt with, but I would say for the safe side that if you arent into doing a lift or serious trimming, these may not be the best bet for you.
I went with the 305/65 and can hardly see a difference in height, sitting at almost 33" (32.7) diameter and at 12.3" wide (versus a true 12.5") I'm happy without the constant rubbing.
AND i can tell you it's so frustrating to try backing up and having your wheels rub the fenders like they wanna rip the truck apart.
Maybe you can sell the tires and get a better fitted size for your ride?