First of all the torsion bar setup gives about the smoothest ride you can find. Plus it takes up a lot less room under the hood than another spring type suspension It is also adjustable. They also allow for front height adjustment with out affecting the ride too much. If you go to a larger diameter torsion bar, it will also stiffen the ride.
The best way to upgrade a torsion bar suspension is to replace the 50 year old dry rotted rubber bushings. New bushings and news shocks will increase the drivability.
I guess we never asked why you wanted to put a Ford front end in a Mopar.