I'm running the Nitto Terra Grappler LT285/75/R16's on stock 16" rims. The tires are supposed to measure 32.68" x 11.33". I've got OME912's, longer rear shocks, and the torsions bars cranked in the front. The trimming/bending I had to do was minimal.

As RichD pointed out, there is no cut and dry answer on how big you can go vs. how much trimming you will have to do because there are so many variables, including the rim width and offset, how far you crank your torsion bars, and even the brand and style of tire. Even small differences in the way the tires are measured due to tread patterns and such can make a big difference as to whether they rub, and how they fit on the wheel.

The Nittos I have actually call for a 8" or wider rim, but on stock 7" rims they tend to bow out just a little bit more, which I think causes them to be a little bit shorter. In other words, they might be more like 32.5" x 11.5".

If I were you, I would look at specific tire / rim combinations that you like that someone else has already done, then ask them how much lifting and trimming needed to be done to get them to work. Otherwise you're really playing guesswork, so I hope you find an understanding tire shop willing to play around with some different combinations for you.