Exactly, Drum Spindle, or Disc Spindle as horsehead has already shown Numbers. The 3108 is Driver by the way, 3107 Passenger.Are they drum spindles or disc spindles?? -- drum and disc spindles will interchange from 1970 to 1973. What are the casting #'s? If you need some casting #'s info I have a decoder book. Post the #'s on them.