Replacement Brake Rotor, For 9 in. Ford Rear Disc Conversion Kit 555-630604 & 555-630616, Plain, Vented, 5 x 5.5 in. for 1/2 in. Studs, 11.625 OD, 7.25 in. ID, 1/pkg|JEGS Replacement Brake Rotor for 9 in. Ford Rear Disc Conversion Kit 555-630604 and 555-630616.