Your present tires are 29.5" outer diameter. Next size up is 245/75-16, and those are 30.5" Good target size unless you really need aggressive offroad tires. 265 width gets into spacer territory, depending on the aspect ratio (the 70 and 75 part of the spec.) and you start to increase rolling friction and then you start to lose 1-3 MPG and many folks think that's too high a price to pay for mere looks.
What did you put on the leveling kit for, and what's your mission with the truck? And what's your budget and tolerance for reduced MPG.
The more you can share, the better advice you'll get.