I have a 99 D2
I have made a manual t handle to engage the factory Diff lock.
question: If all the factory braking systems are working ,i.e. down hill assist, anti lock etc etc, and I have the center diff lock option, do I really need rear/front lockers? Can I improve upon the factory set up?

 

The D2 with CDL engaged and a functioning traction control system is VERY capable and can go most places. I think the better question is...what kind of wheeling do you plan on doing? Are you planning to go to Moab and hitting all the tough trails or are you just using the D2 on easy - mid-grade trails for fun runs, camping, etc? Personally, I would drive it for awhile w/o lockers and learn what it can do and cannot do and then decide if you want to throw down your hard earned money/time on them. Before lockers I would do suspension, good tires, diff guards and rock sliders.

 

You would have to be doing some pretty extreme wheeling to actually NEED lockers. They are extremely capable stock.