Firm Feel , QA1 , Hotchkiss, all offer upgrades
You can take a Mopar past 1g cornering without changing the basic design of the suspension , it was well designed for 1970 , just upgrading the parts involved .
Chassis stiffening has a lot to do with cornering & almost 50% of the cornering improvement comes from just the wheels & tires used , unsprung weight is also very important .
SO I would start with bracing the K frame or replacing it with a QA1 K frame & brace the lower control arms as well as the inner fender braces & lower rad support , factory torque boxes front & rear , subframe connectors etc to stiffen the body up.
Then improve the suspension with balanced upgraded spring rates front & rear , composite rear leaf springs for lighter weight & better spring rate , larger T bars in front & double adjustable shocks front & rear , , you can use modified stock upper control arms or fully adjustable uppers but you will have to replace rod ends regularly . You can use the adjustable lower strut rods , bigger C body tierods & sleeves . You can also increase the sway bars in size & use hollow bars this reduces weight & increases the roll stiffness , I feel increasing the sway bar stiffness is far more important over increased spring rates , increased spring rates can cause the tire to bounce off the pavement where increased sway bar diameter & good shock will keep the tire under control on the pavement . Little known fact but the leaf spring as it flattens on the load side moves the diff rearward & actually helps to steer the car in corners , coil overs & 4 links cannot do this .
You can also use the Borgeson steering box or a firm feel or Steer & Gear stage 3 for better feel .
Keeping the weight low , keeping the leaf springs close to flat , & keeping as much weight in the center of the car & getting close to 50/50 weight distribution all help also .