Tires/wheels 93 Suburban

What is the largest tire/wheel combo I can run on a 3/4 ton 93 Suburban without lifting it? It came used with LT235/85 R16's. They look way too narrow. I want to fill up the wheel well, but not lose any height. I'm getting new wheels, so changing the wheel diameter is not a problem if needed.

I have 265/75/16

Check out this thread for soem ideas:

http://www.automotiveforums.com/vbulletin/showthread.php?t=264120