To find out what your present gearing is, get a piece of chalk. Make a chalk mark at the bottom of a rear tire where it meets the pavement. Make another chalk mark on the rear driveshaft and a corresponding mark on the rear differential. Have a buddy push the Jeep forward until the tire makes excrly one revolution (as indicated by the chalk mark being at the bottom of the tire again. While he's doing that, you lay under the jeep on a creeper and count the number of revolutions that the drdive shaft makes for one revolution of the tire. That number is your gear ratio.