Regear, like Odhinn said. SOME say the wider throttle body makes a difference or a CAI setup will help, but any gains seem minimal.
If you want 33's regear to 4.88 if you have a manual. With my TJ SE on 33's and 4.88, it has about the same performance as the stock gearing and wheels.
You will NOT get the highway performance the 4.0 gets, even with the 4.88, but you can hold 70-75 easily enough until you hit a hill.
Even then, I can maintain 60-65 up the hill for the most part, unless it is a LONG or steep one.