For 1965 & later 3.0L 4-cyl, 135-150 Hp | 4.3L 6-cyl, 205-225 Hp | 5.0-8.2L V8, 270-415 Hp engines.
Spline Hub
ID: 14.29mm | OD: 57 mm
W: 32.5 mm | 12 blades

also crosses with:
Sierra: 18-3276-1