A DIRECT SWAP '71 904 for '70 904 plus... ???

If you are swapping the rear axles and are taking the springs as well, and dont intend to do any cleaning or painting - leave the springs and axle bolted together and remove them as a unit from the donor vehicle, remove the 7 1/4 with its springs and hangers brake lines etc from your car and swap them as a unit.

You save the time it takes to remove and install the U bolts (a pain) and the cost of the items as well. Its normal to replace the axle U bolts once they are removed since the threads and nuts get messed up taking them apart.

The leaf spring hangers are bolted in from the front on each side with 4 nuts inside the torque boxes and two bolts each side on the rear shackle frame brackets. Undo the rubber brake line from the frame and the emergency brake cables from their "U" clips, and undo the lower shock mounts and move them up and away. Bingo......wheel it over to your car and reverse the procedure - done.