If you plan on upgrading your pre '89 rear disc brakes to the '89-'92 PBR "BIG" rear disc brakes which use 12" rotors, then special backing plates will be required for this conversion. We now have available a limited quantity of these hard to find rear disc brake backing plates. They are designed to fit both the 9 bolt Borg-Warner and GM 10 bolt "corporate" rear axle assemblies. They are of new manufacture and have the proper anti corrosive Zinc Yellow Chromate coating. If you are using them on a 10 bolt rear, then our shim kit will also be required, as on the original rears from the factory. The shim kit must be used to adjust the caliper carrier to be centered on the rotor. Otherwise the rotor may come into contact with the caliper carrier while driving. This is especially true if the carrier ends of the axles and/or "C" clips are worn excessively, allowing the axle shaft to have too much end play. As I am sure many of you know these backing plates have been discontinued by GM for years. 

 

NOTE: If you are converting a drum brake rear to disc brakes we have available a special spacer which allows duplication of the original factory installation. This is also available in a complete kit form which includes the special left and right brake line brackets.