Mopars had a very well designed suspension for the day & can handle very well without redesign
I would suggest replacing all the bushings & components , Moog makes good stuff , You can source them from Rock Auto , you can use rubber or poly bushings , Energy suspension makes good stuff if you decide to go to Poly .
You can use the Moog offset upper control arm bushing which when installed correctly can increase the castor adjustment without buying new upper control arms
I would use far stiffer T bars over 1" in diamter as they are under sprung compared to modern cars , rear springs can be sourced through Espo or you can go to lighter composite leafs .
Using a good shock is a must , I would recommend double adjustable .
Hotkiss has far larger diameter sway bars that are hollow as well so they are very light but dramatically better roll stiffness .