I have seen these but (like most suspension problem solvers) they are for the 72-down B-bodies...
You seem to have a well balanced/thought out upgraded suspension package, other than the wandering complaint, How do like it now vs where you started?. Did you note the tire package for us?
Thank you and it's debatable how well thought out it was.
TBH I have never driven the car much with the OEM bushings/shocks in
good shape. I drove it a very little bit when I purchased it back in 2004 but the suspension was
whipped so my frame of reference is limited. I can tell you the FF steering gear made a decent difference (over a parts store box) and the HD tie rod ends took even more slop out. The torsion bars definitely stiffened things up vs stock....they are almost too stiff but better than the "floating" feeling of the originals.
Tires are Cooper Cobras (front P245/60R15 - rear P275/60R15).