Baer Inc. has developed a high-performance front brake system that uses PBR dual-piston calipers on relatively small-diameter rotors, so the whole thing will package inside a 15-inch wheel. Don't mistake that rotor for a milled-and-drilled stock replacement piece. It's actually specifically designed and manufactured for this system and features a beefier casting and directional cooling vanes. The rotor mates to the stock GM spindle (whether disc or drum) of a '67 to '69 F-body as well as '64 to '72 GM A-body or '68 to '74 X-body using stock wheel bearings. Baer also offers an upgrade to EradiSpeed Plus rotors, which feature aluminum hubs for significant unsprung weight savings.