Here is the new design (New in 2006), stronger with the elimination of the use of spacers, lighter for the same reason, and still 3/8" thick for strength and rigidity and it cost less to make so it costs you less! These are for a 14 Bolt Single Rear Wheel housing ('73-87) and use '75 3/4 ton Chevy Calipers & Rotors (not included), no extra mounting hardware needed. They fit both the Full Floaters. These also fit the Eaton axles (pre metric).These make the 14 bolt Disc Brake Conversion easy! Sold in pairs, bolts included.