Quick math (assuming the OD of the 6v [139 tooth] ring gear is approximately the same as the 12v gear) computes to about 2.86" from tooth 1 to tooth 10. Yes, you still have to drop the dust cover, but much easier and less prone to a counting error that hand cranking the engine and counting each tooth for a full revolution.
Last edited by Bill Hanlon; 11/22/2022 12:34 AM.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
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