A couple of part numbers have been used for the rear backing plates; the only difference is the holes in the backplate that accept the wheel cylinder. Depending on which wheel cylinder you are mounting, you may have to drill new holes for the dowel pin in the wheel cylinder. Replaces part number 17H8075. Right hand. Ref: 21A1058.
See 21A1060 for left-hand version.
Note the small inspection hole in the back plate at 10 o'clock position. The rubber plug to fill this is AEU1541A, available separately. Older backplates did not have this hole or need this plug.
As an alternative, see SBR0076 rear brake assembly set.