Many owners successfully use 0.090" or 0.100" shaved from one side. This is a safe amount that does not fall into the grease cavity for the ball joint. Good for about 1 more degree of caster additive to whatever else you use.
The front suspension for very early Panteras/pushbuttons is considerably different than what was used in the first revision for production. Looking at the Illustrated Pantera Parts Manual will show the myriad differences in upper a-arms, steering arm, upright forging and removable spindle. Alignment specs were also different since neither coil spring spacers nor bump-steer spaces were used. This is pure Dallara. Later was Ford engineering.