In 1973, Chrysler transitioned A bodies to what is known as the "spool" mount system. This is where there is a round rubber insert molded into the actual steel mounting bracket. If the rubber should fail, the metal structure surrounds the bolt and will restrict the movement of the engine, so that under full power the engine doesn't lift up and destroy the fan shroud, linkage and other underhood areas. Although A bodies only came with small blocks from the factory for these later years, our special conversion mounts allow you do drop a big block into a factory small block car while keeping the factory small block K member.