The F/M/J body transverse torsion bar front suspension was intended to have a "big car ride". The big cars (C bodies in Mopar Speak) were also softly sprung, huge beasts( i.e. the suspension was designed to be that way). To get that desired (by Mopar management/sales) ride, they created a suspension that was basically made of marshmallows. Come 40+ years later, and people are now used to firmer, tighter suspension, so you can't retroactively apply modern suspension desires onto cars that old. As others have already said, you would need to replace the front torsion bars with something heavier, probably higher rate rear leaf springs, and while you are at it, either add a rear sway bar, or increase the diameter of the sway bars on both ends if both are present as well as all of the bushings and the K frame mounts (with either polyurethane or solid metal). Need to check the tie rod ends (inner and outer) along with alignment. Then you can add better shocks. Shocks dampen the suspension movement, they don't set the spring rates (unless you go to a coil over setup, or something like an Alterkation front end). The stiffness of the suspension is essentially set by the spring rate, not by the shocks, unless they are so stiff as to be almost useless. After all that, you may want to look at the steering box, and the amount of power assist (and yes, it is overboosted, can be fixed with washers if the steering box is in good shape)
