This is a A-72068662 Spark Plug PN: 72068662Main Description As Following : A-72068662 Spark Plug P.N: 72068662 Dim A (1): 14mm ThreadDim B (2): 7/16" ReachDim C (3): 13/16" Hex ShoulderDim D (4): Autolite 216 Stocked As: A-21A873 Found in Section & Models : Ignition & Electrical Parts > Engine Related Parts, Allis-Chalmers TRACTOR: SEVERAL Associated Items : New Also A-AC-S-LPEQUIP And : Dim A (1): 14mm Thread Dim B (2): 7/16" Reach Dim C (3): 13/16" Hex Shoulder Dim D (4): Autolite 216