Need some dimensions...

The problem with using taller rear shackles on a Mopar is that most of the spring strength is forward of the axle and most of the length is behind. Most of the change in height will be a lowering of the end of the spring. More can be had with air shocks or a slight change in the front hanger (will have to be custom). The taller shackles work much better at raising height with symetrical leaf springs (same length front and rear segments).