You’ll just need to crawl under the truck, pull the flywheel pan from the bottom of the bellhousing and measure from the top of any tooth to the top of a tooth that is nine teeth away, as shown in the two pictures above. On a 12-volt ring gear, the distance will be about 2.363”. The same measurement on a 6-volt ring gear will be about 2.789”.
'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.
