Tires and rear differential: You reminded me that the nature of the rear differential REQUIRES the circumference of both rear tires to BE WITHIN 1/4" DIFFERENCE! So you should EXPECT to match the tires like race teams do or suffer the consequences.
What does that mean? Well, you can "confuse" the traction lock unit and you do not want unpredictable transference of drive from one side to the other.
I'm saying what MJ said in a different way about the rear.
The more traction that you have in the rear, the more you need to consider race type chassis bracing. What you need to do to it, you are going to have to talk to someone who seriously races a Pantera.
The other thing with unbalanced rear tires is you WILL burn up the discs in the differential.
You have to remember the design parameters of this car are from 1968. It is not a GT40. It was never considered having over 500hp. The size of even the street treads now were never considered for a street car going that fast then.
Don't forget that race tires are almost always fresh for each race and depending on the longevity are changed several times during that race.
That WAS a pretty blue car. ANY of these items can be lethal.
Sometimes ridiculously stupid things happen at high speed. What I did was move the wipers to the '74 mounting position so that WHEN they suddenly popup at speed, at least it isn't right in my view point. I NEVER expect that simply because I am concentrating on the road. It always startles me and that can cause an over reaction. It's just a stupid thing that happens at speed.