A number of things to consider:
1. Assuming that you have a 4x4 your front axle is 2" wider than the rear to accomodate the front differential and couplings - this limits the movement allowed in the front tires.
2. The Sub frame and fender configuration makes the above even more difficult.
3. The 245/75/16's fit the 6.5" rims that come standard - they are forged, not cast like the 1500 rims for higher strength, better offroad protection and the ability to handle 80 psi tire pressures which can be required with the 10 ply "E" rated tires and a full load in the rear.
While many have put 265/75/16's on these narrow rims, the crowning will reduce tire life, IMHO.
I replaced mine with 8" rims, run 265/70/16's and have a better ride, more control and a proper rim width fit + no rubbing. I would note that my front tires are not technically legal since the bizare "lips" don't cover them - they are there to make the truck legal in NY & NJ - fortunately I live in Texas.
Keep in mind that you will also have to have the PCM reset for the larger diameter - it affects the speedometer, shifting and the ABS.
