A couple of comments here.
First off if you want to increase the front caster past the 2.5+° recommended, then consider putting power steering in the car. You will need it.
What Ford recommended when the U.S. cars were new is all that you need. Some of the numbers some here are suggesting like 5° would be for VERY HIGH SPEED directional stability like if you were racing at Indy at over 200mph. Other then that, you simply don't need it unless you were subject to sudden dip shit fits and are attracted to trees for no apparent reasons.
Keep in mind that most alignment specs are APPROXIMATIONS. It doesn't matter if someone has a computer guided digital alignment machine. It simply doesn't matter if it is off .001° or even more.
As a matter of fact, if you change tire sizes and even tread patterns you likely will need to alter the camber settings to make the tires work. How much? You need to figure that out by trial and error. No one knows that offhand.
High speed rated tires with aggressive tread patterns will certainly require that at some point.
...and if you move away from original springs and shocks to something like Aldens, the car won't move the same way and you need to discover the right settings all over again by trial and error.
The best of the best alignment guys can only put you in the ballpark with them.
Probably the most important setting for both front and rear are the toe settings. You MUST maintain around 3/16" total toe IN or else you are creating a "spin around" at any time "death trap". ESPECIALLY in the rear. You can't have the rear attempting to steer the car. That will happen if you don't have enough toe in and here's the thing, toe in is APPROXIMATE and depends on the tires.
The Pantera is actually a very simple chassis to align
.
Use the weight ballast recommendations of loading the car and if there is a large change required, back it in and out to let the suspension set.
If you are experience with alignments, you can actually do it on your garage floor, presuming that it is flat and reasonably level.
The advantage here is that you don't need to leave it with someone and come back and find they are out driving it "testing".