http://go.jeep-xj.info/HowtoSpeedoGears.htm
You probably want to write down the part number from the list. When I went to get my 32-tooth gear, the computer at the dealership only listed a few(3 or 4) tooth number options when the part was looked up by year/model, and of course the one I needed wasn't on the list. When I gave him the number he found it, and the part fit when I got it. By the way, my speedo gear was overpriced, it cost me an arm, a leg, and my first born son......