The front suspension from a Dart 76 donor, we reuse spindles and calipers but we replace the boot, hose, and seal), the upper and lower control arm are the same of the drum brakes, UCA are "new" (not the original from factory)
Pitman number part are k7076 from TRW, idler arm k7086 from Tread Saver.
Could be the problem? a twisted K frame? a bad tie rod position? tired torsion bars? to have been born in Latin America? China?