I respectfully disagree with whoever is saying you need lockers in your axles right off the bat. I have been wheeling for 7 years, XJs in particular, and I have never had lockers till actually a couple weeks ago. You really learn how to drive when you don;t have lockers. You know to look for the perfect lines for you and your rig. You really learn your Jeep well. I hope someone can understand this. I jumped in a buddy's TJ about a month ago. Built with LAs and 35s, dana 44 and dana 35 rear.. yes 35 rear.. I digress.. I could not drive that thing for crap. I'm so used to wheeling in a XJ, with the wheelbase setup, the feel, the everything, and I couldn't drive that damn tj places i can take my 3.5 inch open open xj without any issue..
Now I wheel a XJ with 4 in long arm and 33s and chase guys around with 37s and up and keep up just fine. Also I'm only locked in the back. I have a ARB for the front, but a stock, locked 30, and 33s is not the best plan.
I see the welded spider gears where mentioned. You may call this the "Lincoln Locker" or a "Miller Locker" whichever way you swing. LOL .
You don't want to weld the front axle, unless you do not want to steer. I would not weld a rear end on a rock crawler but i would in a mud truck. JMO.