Good luck <img src="/forums/images/graemlins/kewl.gif" alt="" />

I think you are on the light side for gears, I have 33's and 3.73 and it is OK, not good. I am confused as to how this gets to stock, my 04 was stock with 30" tires and 3.73 gears, granted it is a 4 speed, but it hunts for overdrive, end up turning OD off so it acts like a 3 spd, Rubicons have 4.10s and 31" tires, stock, is your auto 3 speed, at a minimum 4.1s. Another ?, why not go selectable in the back, then you are only locked in 4WD. Try this http://www.4x4spot.com/gear_ratio_guide.htm

I went with 4.10s, I have only driven it home from the shop, it is a lot different ride, between the gears and rear locker it will take so time to getting used to. Right now the Jeep really just sits in the garage, till it cools down around here so I will not get many mile on it for a month or so. The way I figure it, my speed-o was about 13% slow before, now it will read about 14% faster than actual speed.

With automatic lockers in the front, your stearing gets weird, your turing radius increases, and in off camber stituations the backend will try to swing around, which can be dangerous on tight trails. I also didn't want my front end (u-jionts, etc) to be under contstant stress form being locked up - I will lock up the front end only when absolutly necessary.

I was assuming you had a Dana 35 in the rear and wouldn't want that locked all the time, I guess the only solution is hit the lotto and go selectable front and rear <img src="/forums/images/graemlins/lol.gif" alt="" />

So I finally got to drive the Jeep again, this time tracking my speed with my GPS. I reach 70MPH at close to 3100RPM! <img src="/forums/images/graemlins/scared.gif" alt="" /> It doesn't seam to be straining the engine but this will limit my speed and degrade my gas milage. Althought I rarely go over 70MPH, I have needed to on occation when I was running late to meet for a trail run, etc. this will be a small factor. The rear Aussie locker will take some time to get use to, but is OK, on the road/hightway it is not bad, going from accell to coast back to accell there is very little back-lash/wiggle from the rear end, but there is some every now and then. Taking off around a turn you need to be gentle on the gas, but it is not bad, and all you hear from the rear-end is light clicking, I would suggest this locker to someone looking for a in-expensive locker, especially over an EZ or Lock Rite.

So far after driving it only 3 times I am relatively happy with my choices, I have not taken the Jeep 4 wheeling yet and will give an update when I do.

If you have the 3-speed auto trans and are going to be running 33 inch tires you should consider 3.73 gears, especially if you will be driving the Jeep a lot or it will be a daily driver. I do not know the 4th gear ratio on the 4-speed (2003 and up) but I am assuming it is overdrive, so you should be OK with 4.10 gears, the Rubicons have 4.10 gears stock.

3100 RPM sustained won't hurt a thing.

I routinely pull 3800 RPM sustain climbing very steep hills at 8 MPH in hot weather.

Back when I had 32's and 3.07's, I was using 3rd gear up 2 mile long 7% grade hills at 70.