Beating a Dead Horse

Alright...Yukon Newb here. 97 SLE with the electronic 4x4 shift. I'm not a kid anymore but I still want to have a bit more aggressive tire/ tire size.
I have the factory 17" rims and want to know with a 3" body lift what size tire can I go to from the 265/75's? Probably something like a Kumho /Nitto/ BFG all terrain/mud terrain.

I believe it all depends on the backspacing...I know with my 97 and factory wheels and a leveling kit, I was told i could get 33x12.5's with no modification. I think it might be tight while turning though.

I would say that 33x12.5's would good with a 3" lift...It would also give you enough clearance.