Originally Posted by SoCalRubicon
Lock the rear first.
If you do decide to put a locker on the front you are going to want to upgrade that Dana 30 first.
Agree with this. As long as you don't want to go above 37's, you will not have to replace your rear axle. So lock it as opposed to the front.
Another reason not to lock the front (other than the D30) is because when the front is locked, it is difficult to steer. So if you need a locker on, the rear can be left on with no consequence. Some just leave it on all day. The front on the other hand, has to be turned off so you can steer.
An ARB in a D30 would just be a waste anyway. Do the rear first. Then either replace the D30 with something else, or throw a less expensive locker up there.