Girodisc Corvette C5, C6 Z51 Rear RotorsFitment Note: These C6 Z51 rotors can be used on C5 and C6 base cars with the Z51 rear caliper bracket (GM part # 88964167) or equivalent. The bracket works with the existing calipers and these rotors to complete the conversion to the Z51 brake package. These GiroDisc 2 piece rotors are a direct replacement for the C6 Z51 330mm rear rotor (known as the "J55" or "heavy duty" brake package). Weighing in at 12. 4 lbs per rotor, these fully floating