[john chesnut]

I am not familiar with the T bird IRS so my thoughts are not specific to that unit. There should be a "toe" adjustment link. The pivot point on the inner tie rod should be in plane with the upper and lower control inner pivot points. If you were to draw a line from the upper a frame pivot point to the lower a frame pivot point the pivot point of the inner tie rod should fall on that line. If it's not then the arc of the links will not be the same and will effect the toe.
Essentially the goal is to have all three links, upper and lower aframe and toe adjuster link, move in the same plane at the same rate. Usually the inner tie rod mount is fixed so the adjustment is done at the outer tie rod, where it bolts to the hub. This can be done by shimming the tie rod up or down as necessary. Just make sure that the tie rod is still seated and tightened properly in the spindles tapered hole.
I am not an expert but this is my understanding of the geometry.
Good luck! John