I have a '73 style k-frame in my '70 dart and did a few mods to improve the handling. I used the stock control arms but braced the lowers and used offset bushings in the uppers to increase the amount of positive caster. I have 1.03" torsion bars and they made a huge difference. For now I am running a stock front sway bar and no rear bar. I reduced the psi on the power steering pump by reshimming the pressure relief valve spring. I am very happy with the improvement over how it was stock. I plan to go to a firm feel stage three power steering box, helwig 1 1/8" hollow front bar, bilstien shocks and hotchkis leaf springs. I don't think that you can really compare the handling of a modern car to a vintage car that has been upgraded. The technology has changed so much in the last ten years let alone going back to the sixties and seventies.