Strut Rods
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 .
Theres a couple of ways to get longer upper ball joints.
The one I think he may be referencing to is the Howe upper ball joint. Most circle track race cars use the K727 style upper ball joints. The Howe ball joint is low friction, adjustable lash, aluminum body, and interchangable ball joint pins.
I'm very familiar with these. I have installed and adjusted many of the Howe upper ball joints on the circle track team I helped with.
The Howe upper balljoints are a pretty hardcore piece. Not all the guys in our class choose to spend the money to run them. They are a fine detail item. The low friction is really nice too. But that is only if all the other bushing points are low friction.
They Howe upper balljoint is one of the only ways to adjust spindle height in a relative quick manner. Nice when we are testing different geometries out with the designer of our chassis'.
They do require maintenence. I have spotted them getting out of adjustment mid season or so. That's about ten races 15 or so practice nights, and practice before races.
The other adjustable upper ball joint is a sperical heim joint with a tapered stud on the end to go into the spindle and the other side threaded. You shim the threaded section to get the height you want.