Watch, the earlier/ vs later boxes made a chance in the pitman spline size, about 73. If you get the wrong box spline, and want to use that box anyway, you'll need 4 pieces "which go together"
Center link, idler, pitman, and box spline to match pitman. Regardless of year, these parts must all match, IE all 72/ earlier, or 73 later "or about then."
