Reply to "Shockers and suspension setup."

Adding extra caster on ALL Panteras with wider than stock tires is an excellent suggestion. The max you can get stock is about -2.6 degrees, and for good high speed stability you'll need about -4.5, which you can get without modifying the upper a-arms. The trick? Using offset a-arm bushings to shift the whole a-arm back, which changes the front spindle inclination. Offset bushings in the upper a-arm can increase caster to about -4, and milling one edge of the iron ball-joint carrier about 0.060" will further increase it to about -4.8. Adding offset bushings (oriented the opposite way) on the lower a-arms, the max is now close to -6 degrees, all without welding.
Note that in turns, you're actually LIFTING the entire front of the car a little, so steering does get noticably heavier, but is not excessive. By adding the offset bushings, then repositioning some of the shims, you can trim the caster to better steering stability without making steering effort too heavy for you. Offset a-arm bushings are only available in polyurethane here in the U.S, which increases steering precision. All the U.S vendors sell them, and road noise does NOT increase with polyurethane, as was once claimed.