This ^.
I had my Mustang do this once. Squealed and darted back and forth on the road. My dad and I had done a tie rod adjustment to adjust the toe-in, and hadn't tightened the sleeve bolts enough. They had loosened up just a little, causing toe-out and the symptoms and noise I described.
Now my dad was a heck of a mechanic and wouldn't believe it until I showed him. There was at least 1/4" static toe-out, and who knows how much dynamic toe-out with the sleeves loose.
We readjusted it & really tightened them down & no more issues. We used to adjust the camber by putting a large magnet that had a flat back edge, parallel to the front, on the disc rotor. Put a bubble level on the back side, and adjusted the eccentric cams that car used until it was good. Was able to measure the castor satisfactorily that way, too, by knowing how the camber changed as the tire moved from full in to full out. Learned to adjust caster, then camber, then toe last, as the previous item affected the others. We did as good as any shop would have.
Great times working on that '67 Mustang fastback with my dad. Modified the front end geometry to match the Shelby's. Good stuff.
Gary