There is a company that makes a chip upgrade:
www.powerchipgroup.com
Also worthwhile doing is to replace the radiator fan with an electric one.
There are relatively straightforward ways of doing a lift using spacers or new springs.
More ("hardcore") details at:
4x4Wire.com's TrailTalk Forums: Viewing list of forums
(Moderators, not pimping for new members, but all the relevant info is held there)