Hey everyone it's been a while since I've posted anything but I thought I would share this because it looks like a good set-up! It's a NP231 doubler crawler box you can attach to a NP231/Dana300. here is the thread That a friend showed me on Pirate4x4.
http://www.pirate4x4.com/forum/showthread.php?t=399755
there are 1 other companys making them also: d.d machine : box4rocks both have posts on pirate 4x4. From what I gather you could have in my case with Dana300 2.6-1 and 2.7-1 reduction doubled 5.3-1 low range or either 2.6 or 2.7!!! The kits all run around $350-$500
check it out!
http://www.pirate4x4.com/forum/showthread.php?t=451754
http://www.pirate4x4.com/forum/showthread.php?t=484900

nice idea, but what is the overall length of the set up?

It said that it will add about 8" to your current set up. I read in one of the post that it is shorter that a stock NP231 w/o a SYE. There were a few different post on pirate4x4. It's a lot cheaper than a Klune-V !!!

im confused. why wouldnt you just throw the D300 under there have a twin stick and get a 4:1? seems like a lot of trouble, and for what? also would the rear drive shaft have to be shorter than it already is? how much are 4:1 for the 231 going for right now?

You could just put a 4-1 dana 300 under your jeep, but if you wanted more transfercase options than just 1-1 and 4-1. like stock d300 2.6-1 or the wrangler box 2.7-1 or combined 5.3-1!!!! if you just play in the rocks then 4-1 is great but for other areas you have the option.