We did this van 2? years ago for a local customer. It's about to be shipped across the pacific so it came in for some improvements. He has complained about the steering feel since the beginning so I talked him into going up another 2" on the coil conversion and updating it to x-over steering with a relocated trac bar. It's my belief that the drag link/trac bar angle was too steep and the non forgiving radius arms don't allow the axle to move in an arc (the way it has to with the angle of the trac bar) so this is what causes the bump steer and overall vague steering feel. In some cases, death wobble. I went thru all of this before when I made the coil updates, not looking for another S show debate
A flatter drag link and trac bar is always better, I've already proved it even though some don't want to listen.
The others we converted to this steering are still 100% happy after many many miles and are glad they did it. We don't have any more parts to do this again.