AAR and T'A's used a unique leaf spring as mentioned above. Here is a side shop of originals showing the unique high arch. Also not they are only 4 1/2 leafs
AAR's and T/A's also used the standard "B" body lower shock mount. (also same shock mount used on 71's) THE MOUNT ON THE LEFT AS SHOWN IN THE PHOTO ABOVE
This was done because the ride height in the rear was higher (to presumably clear the factory exhaust) and allowed Chrysler to use the same legnth rear shock without having to have a special part.