I just had new 4.10 gears installed and was feeling on top of the world.

The diff shop said to break the new gears in 15--20 mi at a time for the first 200 miles, with a minimum of 30 minutes between sets. I did all that. I was up at 4:00 this morning, and put on the last 60 miles by 7:00 or so. Actually, it's been great. It's nice to have some acceleration again! New gears = good. Good, good, good.
So, my wife and I set out on Reddington Pass road. We live 10 or 15 minutes from there. For those in Arizona, I'm ashamed to say I haven't been on it much. For those from elsewhere, here is someone's picture:

I hadn't really planned to use 4WD until I had 500 miles on the gears. But I was told I could do whatever I wanted after 200 miles. I was having a little trouble in 2Hi so I put it in 4Hi and we went that way for maybe 10 miles. We saw a rest / staging area and stopped for a pit stop. At that point I saw what appeared to be water in the front driver side wheel well.

Upon closer inspection, it turned out to be grease!

Presumably, C.V. joint grease.
Otherwise things didn't look too bad and I wasn't hearing any noise. We weren't more than 20 mi from home, so I put it in 2WD and limped home. It was early in the day, so we transferred our stuff to my wife's Subaru and we went to Saguaro Natl Monument West and went hiking. So it was a good day anyway! It's good to have a backup vehicle with a little bit of ground clearance and AWD.
When we got home I crawled under the Jeep and inspected the area around the driver side half shaft. It is definitely a very viscous grease, and not oil. It looks like new grease: thick with a yellow-green color; and not old black, thin grease. It is the inboard side of the half shaft, by the differential.
It looks like the grease is getting thrown upwards onto the strut and thereabouts, and then dripping onto some other components like the lower control arm. There's so much grease that I thought the boot must be torn. I felt around some with my hand and couldn't find a tear. Didn't try real hard as I wanted to preserve the evidence, as it were.
I see no evidence of problems with the front differential itself. So at this point I'm thinking it's just the CV joint boot or at worst the CV joint itself. For a lifted KJ with 83K miles on it that just had its front differential dropped, it's not surprising that there's a CV joint problem. So if that's all it is I'm relieved.

One more little thing. When I checked my tires first thing in the morning, I noticed that one lug nut was missing from each of the two front wheels. I had to rob two nuts from my spare carrier and put the spare in the cab. The one on the driver side with the CV joint went on fine. The one on the passenger side did not because the stud was stripped. Mainly a red herring and no big deal as studs can be replaced. The point though is that I spent quite a bit of time around the front wheel wells and didn't notice the grease. So I'm thinking the CV joint probably started spewing grease only after I went into 4HI. Does this make sense?
If it's just the CV joint that's not a huge deal compared to the differential and I just need to fix it. If it's just the boot, then it's just the boot. If the CV joint needs to be replaced, then I have one huge question. More than anything else in this post, this is what I want to know. Can I go with the OEM CV shaft, or should I go with the higher dollar J.E. Reel shaft with 3/8" of material removed from the inner joint face??????
Here is the JBA link:
http://jeepinbyal.com/prod-CV_axle_shaft_driver_side-489.aspx, and here is the link to J.E. Reel:
http://www.reeldriveline.com/catalog/ I can't find any references to the KJ at the J.E. Reel site, but JBA lists them as the manufacturer. I'm not exactly sure how much lift I have in the front, somewhere between 2.5 and 3".
I have no problem spending the extra $250 for the special shaft if needed. Mainly I'm worried about lead time. I'll bet I can get a new CV assembly tomorrow from the dealer. Whereas it will take the better part of a week to get one from JBA, assuming they have one in inventory.
???
Any input is appreciated as I have to move on this tomorrow (Friday).
Ernie