Does your Duster "float" at highway speed?

1975 Duster 318 with Power Steering and mostly stock style suspension: I'm currently having this same problem and no help from the alignment shops. Two of them, so far, have sent me home with my wheel turned 90 deg. to the right and said they couldn't fix it (fixed it myself). They could only achieve about 1-2 degrees caster, but also added back rubber behind my strut bar mounts, reducing caster. Mine used to track fine on the freeway at speeds of 80+ with old suspension on old tires. I recently rebuild the front end with .940 bars, new bushings, offset UCA bushings, ball joints, tie rod ends. Adjusting my wheel straight, and therefore centering the range of travel on the steering gear helped a bunch, but it's still not good on the freeway. My next move is adjustable strut bars to maximize caster just short of causing binding in the LCA. I do have one LCA pivot that wollowed out years ago and I had modified a strut bar with threads and jam nuts to compensate. Might just be the key here. Anyway, that's my story - good luck and keep us posted.