Use with GM block code (4XA, 4XF, 4XW & 4XY) Fits: MCM 496 Mag (s/n 0M667238 and up) 496 HO (s/n 0M672041 and up) MIE 8.1S (s/n 0M316948 and up) 8.1S HO (s/n 0M316894 and up)