The stock "spring perch" was a pivot. Works with the torque tube. With an open drive shaft the axle housing needs to be clamped firmly to the spring(new "U" bolts and plate required) the spring perch is welded to the housing( to secure the pinion angle). If you want, drill the perch to center the axle in the wheel opening(yes the center pin will be a bit off, but it will be "off" when the springs are reversed). No real good reason to reverse the spring.
