Seth, you shouldn't need a body lift -- the SEs came with 31s stock from the factory. Maybe your torsions need a bit of a crank? Are you having trouble with your tires hitting your bodywork? Got any pics? How do you like your 31s? Sorry to jack your thread.
I think cranking your torsion bars and putting in an add-a-leaf or taller shackles in the rear would be helpful for you. I don't know if they make blocks for the Nissan trucks or not, but that may be an option over a body lift. We had 2" blocks on a Classic Cherokee one time and did LOTS of off-roading with it and never had a problem.