The problem with the D and larger tires is mostly the width. Tires equivalent to 11.5 and larger diameter will rub the frame on turns on the front end and will rub the rear wheel well insides on full articulation of the rear axle. You could check with a tire shop about a different offset rim for the wider tires. You can run a 32" tire without too much trouble in the front. Any larger and you might have to trim some of the front bumper at the wheel well openings. You still might have a problem with frame rubbing. Of course if you put on a Hanson bumper, you wouldn't have any trouble with wheel well opening clearance for larger diameter tires.
The torsion bar/shackle lift, or torsion bar/add-a-leaf kit might be the way to go. With the add-a-leaf kits you get a full 2" lift in the back and you get about that in the front by tightening the torsion bar adjusters. This lift is also much cheaper and easier to do than a full lift kit. Hope that this helps.