[67C10Step]

If all the disc brake stuff is already on your truck perhaps you just have an outer tie rod issue where the PO did not realize they needed later model tie rods to attach to the disc brake spindles.

Now, if it were my truck I'd go over everything, inner/outer tie rods, ball joints, etc. If the PO didn't get the outer tie rods right I'd want to make certain they got everything else right before trusting fully.

From your description and not knowing where the spindles came from it would be hard to say if you need '69 hardware or later when it comes to ball joints. Sounds like you need later model outer tie rod ends which may mean you need new adjusting sleeves to accommodate your inner tie rods and center link since they would be different from the larger outer units.