go low
You can't really lower a 1st Gen 4WD that much because the limited travel of the TTB up front would have it riding on the bump stops, and as mentioned, the oil pan is also in the way.
Eibach makes a coil spring kit for the front that goes right in and lowers from 1.5-2" depending on trim level, weight, options, etc. Have the rear springs de-arched (or just get a drivers side spring from another '91-94 and install it on the passenger side, plus you can remove the load sping from both packs for a lower height and softer ride). Some have shaved some material off the front bumpstops to get slightly more suspension travel before it bottoms out, but you want to be sure there is enough material that the TTB will NEVER hit the oil pan. Be sure to add some quality shocks with this mod. You might also want to install a polyurethane bushing kit, at least for the swaybars, or just upgrade to the thicker swaybars to go with the lowered look. Oh yeah, and larger wheels too.