Hah hah. You've been talking about these axles for at least a year are you ever going to install them? 
If I wanted to put 60's in I would save up and do it. Don't need them though it would be a waste of money, I actually plan on staying with my 4 cylinder and not going larger than 35's. If I ever want something bigger I'll build a buggy.
If you are not going any bigger than 35's and keeping the 4cyl, I strongly suggest you rethink the expense you are going through. From what I've read, you want a differential housing that would give you 5.38s and work with the stock D30 knuckle out. Problem there would be the inner axle length as it could become a custom length, thus requiring machine work. If you break a u-joint, most of the time, you break/mess up the ears on the axles and need to replace both of them. However, it's highly unlikely also, (very driver dependent), that you would break an u-joint and thus both axles. But, it still could happen.
Now, Dodge has been selling the newer JK front and rear axles with gears and lockers in the ready to bolt in and go. They are 5 on 5 lug pattern. They are 5" wider (someone stated under 3" but no clarification on which is correct*). Supposedly, the locations for the coils, control arms, and track bar do not need relocation. They are D44 housings, front is high pinion. Since they are still fairly new in the market, aftermarket will probably have different ratios/lockers available soon enough.
I'd see about if these JK axles would work with the TJ D30 knuckles out. That would be a fairly good swap to the TJ. Using stock TJ components where needed to keep costs down, empty axle housings from Jeep with inner axles (or look for aftermarket alloys) will keep costs down, you getting your own gear/locker and install will keep costs down, and you can actually keep you Jeep on the road during the install since the suspension components won't need relocation. So it may only take a day to swap out the axles, remove/install knuckles, etc. Not bad for a weekend.
Now, another viable option and probably a way to make some money at it is to come up with a gear case that is 30% lower than 1 (1.3:1). This is what 5.38 ratio is to the 3.73 ratio (assuming what was stock in the 4cyl TJ). This would be pretty simple and you wouldn't have to make it have any real length, maybe 2-3+ inches. The gear case would be similar to that of the Klune, but you wouldn't be as long as you only have 1 gear ratio change using the planetary gear setup. Place this between the trans and t-case.
My followup question is to why do you need the 5.38s in the axles (did I miss it)? Is it for 2wdhigh or the 4wdlow side use? If 4wdlow, you can getter low gear ratio for the TJ's 231 case. 4:1 is rather easily available, its a bolt in situation, and a much better option for your money's worth?
You could also look at D.D. Machine's doubler for the 231 as a way of getting better low side gear ratios.
*Not to push to another forum, but JeepsUnlimited has someone that install JK axles into a TJ w/ pics.
