Let us know a little more about what you want your jeep to do. Shackle reversal yeilds better ride on street and faster type offroading, but with slow flexy wheeling, shackles on the front of the spring work better. with shackles on the front, as the tire moves up it also moves forward a little, puting pressure on the tire (better traction).with the shackle on the back of the spring, the tire moves up and back, unloading pressure from the tire (less traction)
its all about personal off road style though. shackle reversal can be good in many ways or bad in many way