Im running Toyo Open Country AT3s on 38mm offset HMC HM708 Bullys.
You might be able to run 265/70-17s in a Road tire as the shoulder is more rounded vs an All Terrain.
Maybe someone else will chime in.
Wheel KMC BULLY 17X8 38 offset.
Bottom picture before lift: Blizzaks DMV2 245/70R17. No rub at full lock.
Top picture after 2F2R lift: Cooper Discoverer AT3 4S 245/70R 17. There's a very slight rub at full lock over a bolt (see pictures).
I wouldn't go any wider or taller unless you are willing to trim and cut. Also, different tires will fit differently. Cooper Discoverer is very compart for AT tire. For example, FALKEN Wildpeaks will rub a bit more since they are more square/bulkier. 30.5 I the biggest you can go with no or minimal rub depending on the tire and/or lift.
30.5 will fit without lift or with lift (lift might cause a bit of rubbing).
If you want a bigger tire, look up Traxda axle relocation kit which will move the front wheel 1 inch forward. This will allow you to fit 32.1 tire with some minor triming of the plastic in front of the wheel (the back won't rub). Traxda fit 275/65r18.