Installing new ring and pinion gears is pretty tricky. Bolting the gears in appears to be pretty easy. But, they have to be adjusted perfectly or they can make weird noises or wear out in a few hundred miles. This requires specialy tools and experience.

 

A stock Jeep, even a X/Sport, can handle some pretty amazing stuff off-road. It's just how difficult to you want to go. And, when you go more difficult, you make the previously difficult stuff not really a challenge at all. 33s and a 2" (2.5" in the front to level rake) is a great look on the Jeep. Some argue that 35s look a little better on four door Jeeps--but that's all subjective. I went plenty of places in my Jeep with stock SRA tires and no lift, then later with 33s and a 2.5" BB, and now 35s with a 2.5" coil lift (which gives much better articulation, making technical spots a lot safer because there are more wheels on the ground). If you know for sure you want 37s, don't let me dissuade you--certainly plenty of people are running them. But, as already mentioned, the bigger you go, the higher you must go. The higher you go, the more expense you incur with additional parts.

Gears: I've done all the mod's on my Jeep ... except gears. I paid someone to do that rather than risk causing damage to my axles.

 

Thanks everyone for all the great advice I really do appreciate it ! Now it's all about decisions lol