Tech Up 45 Research has seen two OEM clutch pulleys that are dimensionally the same on the outside, but use different rotor thread sizes. (used with different rotors) 24-2279 OEM F-22997.4 uses M16 x 1.50 thread. Ford 6G Dimensions: 21mm Belt x 60mm OD x 17mm Bore 24-2279 M16 x 1.50 Int. Threads 24-2280 OEM F-232600 uses M17 x 1.50 thread. Mazda Mitsubishi. Dimensions: 21mm Belt x 60mm OD x 17mm Bore M17 x 1.50 Int. Threads 24-2280 — | ee | i 24-2279 is used on alternator 3L7Z-10346-AA, 3L7Z-10346-BA WAI 1-2533-31FD, Lester 8303. 24-2280 is used on alternator A3TB1081, WAI 1-2377-01MI Lester 13883.