This is a A-163981A Input Shaft, Transmission PN: 163981AMain Description As Following : A-163981A Input Shaft, Transmission P.N: 163981A Dim A (1): 12.500" LongSpline Count: 27 & 18 Spline Crossed From: AM163981A , , 163981N BMD MFG Found in Section & Models : Transmission & Rear Axle > Trans: Forks, Gears, Shafts, White/ Oliver/ Mpl Moline TRACTOR: 1950 (SN 189007->), White/ Oliver/ Mpl Moline TRACTOR: 1950T, White/ Oliver/ Mpl Moline TRACTOR: 1955 Associated Items : New Also A-DD-S-53SERIES, A-FRM-OLLATE, A-OL-O-1950, A-OL-P-1950, A-OL-S-18501950, A-SMO202, A-FRM-OLLATE, A-OL-O-1950T, A-OL-P-1950T, A-OL-S-1950-T, A-SMO202, A-WH-S-TURBOS, A-FRM-OLLATE, A-OL-O-1955, A-OL-P-1955, A-OL-S-17551855, A-SMO202 And : Dim A (1): 12.500" Long Spline Count: 27 & 18 Spline