Welcome to the forum.

The best mod by far is a locking rear differential. There are many options to choose from, from fulltime locking diff to a selectable manual locker.

FYI a 02 4Runner does not have torsion bars. You have a coilover shock/spring instead. You will want to keep the lift under about 2.5", otherwise you will max out your ball joints. I'd suggest a differential drop at the same time you do the lift to relieve your CV boots to make them last longer. I'd go with a cornfed spacer lift if you want cheap and easy. Otherwise, go with some OME (Old Man Emu, from ARB) springs and shocks.