Need advice help.

Short version. You can use the steering components you have now if you swap the complete package, steering box, Pitman arm, center link, idler arm, tie rods, onto your '73 K member. You will also need '73 up lower ball joints for disc brake cars. You do not need new upper control arms if you get Dr. Diffs upper ball joint adaptors available here http://www.doctordiff.com/a-body-upper-ball-joint-tapered-adapter.html Hope this helps...