4.3L XJ

Hi folks. I am in somewhat of a quandary. I have been redoing and rebuilding and now to the build up phase of my XJ. The Atlas 4 speed is in and it is time to start thinking about my new rear axle. It is time to consider installing it and regearing it. I am torn between running 37X112.50X17 BFG Mudterain KM1s with 4.88 gears or going to the KM2s in a 38X14.50R17 with 5.38 gears.

Anyway, input is appreciated.

broncofire75

With the Atlas I'd go with some 4:88s and 37-38s. What's the gear ratio for the case?


Have you considered any other tires? Or is this gonna be driven on the street a little since you chose BFGs?

COSXJFAN

Yeah, I need to know the intended use of the rig first to answer properly...

4.3L XJ

Yes, it will be driven on the street and by my wife from time to time. The ratios in the atlas are 1:1, 2.62:1, 3.8:1 and 10.38:1. That what was recommended by Advance Adapters for automatic trannys.

4.3L XJ

This is going to be a true multipurpose rig. DD, sand, mud, rocks and snow. I am intending it to be very good at every situation, but not necessarily the best.

a1racer

for that size tire the 4.88 would be the bare min i think and more like 513 would be better. and post up some 4 speed tcase pics for use poor folk

4.3L XJ

I was working on the linkage today. I might get some tomarrow

92xjhammer

one of my best freinds just recently put a ford 8.8 ion the rear and a dana 44 in the front end. he is running 38 in tsl's and he has 4.88 gears and that thing is a champ on the road and wood.

COSXJFAN

At the very least 4.88s, if not 5.13s. If it were me I'd gear a little to the low side, AKA, 5.13. HTH!!

a1racer

the 488's will put you in the same boat of the 33's with the 355's you need to go lower for that size tire 513 is your best option and will fit with the setup you are running.

4.3L XJ

Clocked and on the tranny







Finally in

Cj.stuff

Looking good!

xjoffroad

yummy an atlas! I would go with 37-38's with 5.13 gears. Do they have to be a BFG?

xjmarc

I'd go with a 4.56. With that low of gearing in the Atlas with it in Lo Lo Lo (10.38 to 1) you will barely be able to hit 15mph at 4 grand. Also good luck finding the KM1s.

dirtmod0

nice combo! i would probably go with at least a 4.56 gear esp. for street. i noticed the one pic of exhaust real close to the front of trans, I am hoping you plan on putting some exhaust wrap there, my brother cooked his running by that. the third pic..