This system features the S4 4-piston caliper mounted to a 13", 2 piece slot, drill, zinc plated rotor. The S4 caliper has D.O.T compliant dust and weather seals and uses the popular DR1 or HB100 pad type. Rotors are pre-assembled with NAS high grade stainless hardware. Baer's unique backing plate not only acts as a caliper mount, but also houses a modern 1-piece park brake shoe assembly. Stainless braided hoses are also included. The 13" SS4+ fits most 17" or larger wheels. | Rotor Size/Type: 13" x .810", 2-piece | Replacement Rotor Rings: 6910922 (Left) / 6920922 (Right) | Caliper/Piston Count/Mount Type: S4 / 4-piston / Lug | Replacement pads: DR1-C | Minimum Wheel Size: 17" or larger (Use template to verify fitment, link below) | System Includes: Calipers, Brake Pads, Rotor & Hat assemblies, Brackets, Park brake assembly, Stainless braided brake hoses & system hardware. System incorporates Baer's unique Verislide design allowing the calipers to float with the factory c-clip axles, Does not include park brake cables | Notes: Designed for c-clip rear end | Applications: - 1971-76 GM full size passenger cars with OE 10/12 Bolt c-clip rear end