You've got 4.3. I've got 4.9 on my Gen3. Running 33 don't feel much different except for dismal mileage. I only felt real strain towing my popup at high altitude, or going over 75 mph. <img src="/forums/images/graemlins/ignore.gif" alt="" />
4.9 will make nice difference on and off-road especially considering low 1 gear you have. In 1 gear low you'll have reduction almost matching Gen 2 or 1 with AUS 2.85 gears)

92 SR, 285/75R16 Yoko MT ARB locker GAST compressor AirLift 1000 MM10500 Snorkel custom rear bumper
02 Montero LS died protecting the master
08 PowerWagon (stock!)