My truck had a 6 inch lift, which I did not like, and so I made some standard height shackles, to see if I liked the ride. It was Ok so when I got round to it I bought some 85mm center greasable shackles and pins. Have attached how I went about changing them.
1. Undo all nuts while vehicle in on the ground.
2. Jack and support rear end on axle stands
3. Undo nuts and use a floor jack from underneath or sissor jack at top to there is no tension on shackle side plate.
4. Use a mallet to drive out shackle pins, then a punch. (Mine where still pretty loose).
5. Remove old shackle.
6. Pic of new shackle with factory with 85mm pin centres
7. Grease pins, and place anti-seize on threads.
8. Tap into place with mallet.
9. Loosely fitted in place.
10. move to other end of spring, Undo 12mm AF nut.
11. Use scissor jack at top or floor jack at bottom to remove tension from pin.
12. If pin turns when removing nut place punch in hole to stop it turning when using wrench.
13. Remove nut and tap out pin.
14. Use jacks to align hole.
15. Grease pin.
16. Tap into position and loosely secure with spring washer and nut.
17. Repeat for front.
18. Remove axle stands and jacks, tighten all nuts, fit grease nipples and greas, all done.