I really, really suggest running it stock for a while. Go out on trails. See what kind of wheeling you enjoy. See what kind of trails are available in your area. Find a local club and go out with them. See how they have their jeeps built. That will give you the proper perspective on what you may want to build. As others have said running 40s is a big investment in other things. I run the RK 3.5 with 37s. I am running stock 44s until they break. Then I will upgrade. I have been looking at the dana ultimate 60s.
Once you start adding all of the smaller things, bumpers winch, armor etc, the added expense of trying to reliably run 40s pretty much doubles everything else you spent. If you want to take the chance and run 37s plus on stock axles just have the money available to spend at a moments notice for all new axles. If you do not have the ability to spend $11k+ if it breaks, then go with a smaller tire. Almost forgot nee rims for some 60s due to bolt pattern.
Realistically, to run 40s you cant be cheap on anything, or you will be buying things more than once. I will look forward to your build thread once you decide.

 

i dont mind putting in the money and time to do it right. i def. want bigger than 35s...would yall recommend doing 37s instead?

 

37s would be a better starting point.

 

so should i go down to 3in. or stick with 3.5in

 

i've had my jeep for a year now and go trailing a good bit. great advice though. imma go with 37s with 3.5in lift. and the 5.38 gears for now and slowly build it and beef it up and then eventually slap 40s on it. thanks for the input

 

Everyone has given you good advice for sure. 37s will be a much better starting point for you.

The 3.5 X-Factor and 37s with flat flares is an awesome setup and the Jeep will go anywhere you want it to and then some.

You don't want 5.38s in that 14 and you can't go any deeper than 5.13 with the D30 up front. Stick to 4.56 or 4.88 with an auto and maybe consider 5.13s for a manual transmission.

This is my 2012 JKUR. It had a 3.5 X-Factor Mid Arm, 37" MTZs, and the armor was all Poison Spyder. I re-geared it to 4.56 and was happy with the results, but I live in an area where we have speed limits of 75 - 85 MPH, so I went what some might consider a little light.







I ran around with stock flares while my Poison Spyder flares were being painted.



Marcus

 

I like my 37s w/ the 3.5 RK lift. I am running 4.88 gears, which are fine for the freeway, but I wish I would have went w/ 5.13s for a little extra power going up long grades. The 5.38s are good for 40s, but I hope you don't have a heavy foot. I got 10 mpg in west texas going 80 mph (the speed limit) as I drove from Ca to Louisiana. I use a 3 inch bumpstop, could maybe go 2-2.25, just worried about bottoming out the King shocks.

 

Slap on 40's, Sweet!

 

Yes, yes it can quickly escalate in price......i paid off the jeep, but had to finace the mods..lol

 

I hear that 42's are all the rage!