Hey Eric, am I hallucinating again or did you originally have a Watts Link in that chassis?
@freethinker... the triangulated non-parallel upper arms also locate the axle side to side, doing the job a panhard bar would do. The down-side is that unless the ends on those upper arms can swivel (the factory ones don't but many aftermarket replacements do, and it looks like Eric's probably do too) the upper arms can "bind" and resist allowing the axle to freely move in a body roll situation like in a corner. The factory triangulated arms used rubber bushings everywhere so they could deform and allow some roll movement, but they still bound up. As a panhard bar moves up and down through its arc, the axle moves from side to side a little bit. With a Watts Link, that doesn't happen. The axle stays located in the same spot side to side but is still free to articulate in all the directions it needs to.