steering coupling

The power steering box takes a small (5/8") spline coupler, a manual steering box takes a large (3/4") spline coupler. If the 72 and the 75 both have power steering the couplers will be the same. The center link, pitman and idler arms will be different between the 72 and 75, however either style will bolt up to any 68-76 A body K frame.