Who makes the longer than stock upper ball joints? What these will accomplish is a lower roll center location and would also likely improve the camber curve. This of course will improve cornering ability. To fully understand the effects you would have to use some suspension software.
Another way to accomplish the same effect is to use F-body (Aspen/Volare) spindles on an A-body. They are about 1" taller.
The longer upper balljoint have been available for GM's for years for use in oval and road racing. I did not know they were available for mopars .