Actually guys you can squeeze 35's on the 3/4 tons w/ a leveling kit and trimming. There's tons of trucks running around w/ them. Head over to dieselplace and you'll see. Notice how he cut quite a bit out of the front bumper and air dam. Looking at the amount of space that's filled up in the rear wheel well, and combining that w/ the huge amount of trimming.... I'm leaning more than ever towards 35's.
Here's an example of a duramax w/ 35x12.50/20 w/ just a leveling kit. http://i76.photobucket.com/albums/j31/builttaco/UltimateUnlimited/CIMG0394.jpg
(Message edited by Tanner on March 30, 2008)