Thanks for the reply. I agree about the rod end on stud threads but the only way you could stay off of the threads would be to use a hardened sleeve over the threads and probably the shims. That capability is not in the design of any of the readily available "ball joint studs".
Again, we don't need to speak in generalities here. We are speaking of the Pantera by folks who have raced the Pantera. Yes on all suspensions as the hub rises and falls, there is a change in toe since the hub center is acting through an ark.
The point here is that since we are talking specifically Pantera, the change without the shims is know (known by someone) and the improvement using the shims is know by someone.
In addition, going through the BossWrench modification, the improvement IF ANY is known by someone.
If an 1/8" change is stock and it can be reduced somewhat with lowering and further improved by the additional BW mod that would be nice to know in advance.
It isn't a criticism of anyone here, I'm just pointing it out that it is under these conditions, no longer just a generality, the numbers are known.
In my GT350, when I lowered the upper a-arms in what is called the "Shelby modification", the bump steer change was horrendous. The car would hit a bump and change lanes suddenly and harshly. That originally was with bias ply tires though and radials reduced if almost eliminated the jerking steering wheel.
I installed a "bump steer eliminator kit" and there is no felt reaction to the steering wheel now.
I'm going to take a guess here and say that the BW modification is most likely unnecessary on even a hard driven street car, but I don't know that as a fact, but it with be nice to know (translated as: I suppose it would amuse me).
This thread unfortunately has suddenly gone no where fast.