I'd say you could get your Challenger to handle very well, considering they're 32+ years old...The whole idea of getting to that point of a nice curve handler can be produced two different ways:
a) Purchase an Alter-K-tion or other coil-over shock setup along with rack & pinion steering, but pay a premium...
Or
b) Improve upon the original K-frame and suspension components, which will save you quite a bit in the long-run and provide a comparative advantage to the much more expensive setups. As you may know, quite a few different steel components can deflect under hard cornering and throw off the suspension geometry during that time. One way to correct this is purchase the LCA (lower control arm) gusset/boxing kit. When completely welded up, the LCA has less of a chance to flex and therefore won't throw off the geometry. Another way to help in cornering is to increase your torsion bar size to allow for harder turns with less 'mush'. If you wanted to use the original UCA's, you can purchase offset upper control arm bushings that will allow you to get more positive caster, or if you wanted to, purchase a set of tubular UCA's with heim joints that will allow you to really dial in the caster. Another possible way to help out is purchasing the larger strut rod bars to either replace your old bent ones or just to get better deflection off them. The tie rod ends have been known to be rather insufficient, considering the weight of the car. One way to fix this is purchase a set of 11/16" tie rod ends (from C-body MoPars) and either use their adjusting sleeves or step up to the solid adjuster Mancini Racing or any other race shop carries. Again, deflection is limited by stepping up to these, rather than using the smaller 9/16" tie rod ends.
Hopefully this helps you out any. I'd know the direct effect of all these things mentioned in part B, but I haven't gotten around to assembling all my parts yet. (still need some areas that were covered by the suspension cleaned & repainted.)