Are suspension parts differernt for a V-8 K frame and the slant 6 K frame?
My Duster is getting down right scary on the freeway!............ I never changed the bars. Its been like this for 3 years. ......
So did it used to drive OK, and got worse, or has it been scary for 3 years? Which is it?
Because.............
1----If it's "getting scary" that is, it used to drive fair, but got worse, something has changed, broken, worn, and IT IS NOT T bars, although T bars would certainly improve handling
3----On the other had if it's "been scary" for all 3 years, and has pretty much stayed that way, almost anything is possible.
But the COMPLETE answer is to suspect EVERYTHING. And check everything. If you have never rebuilt the front end, I would just ASSUME that a 30-50 year old car has worn out the front end.
But this does not discount the possibility that something has BROKEN such as the LCA anchors in the K member, etc.
On top of everything else, TIRES can cause a car to drive unbelieveably evil, and don't leave out the REAR suspension---something loose/ broken back there
Get the car jacked up under the LCA so the weight is on the LCA, and pry on the lower ball joints
With the car on the ground, and a friend to move the steering back, forth, LOOK for play in the tie rod ends, up/ down play in the idler arm, or any other play in any of the joints in the tie rod chain.
LCA bushings are difficult to REALLY check. If they are pretty bad, jacking up, releasing tension on the T bar adjustments (count the turns) and then prying on the LCA, but they have to be REALLY bad before this shows up.
Frankly, I'd just tear it apart and rebuild it.