Hello group. I have a 77 GMC 1500 with what appears to be a 10 bolt, 8.5" rear end (the truck style with the 12 bolts on the cover, and the irregular shape - photo attached). I ordered a rebuilt kit for it as the bearings appear to be needing replacement, and thought I would check out the gear ratio as well in case I pull it apart and find I need to order a new ring and pinion for it also. In my test, 1.9 full turn of the drive shaft yields exactly 1 rotation of the rear tire. This seems like a crazy high gear ratio. I am thinking someone put in an unorthodox mix of ring and pinion gear to achieve this? Has anyone else ever found such a high ratio from stock? The truck has factory cruise control on it, so someone at some point in the last 40 years did a lot of highway driving with it. I measured the ratio 3 times thinking I made a mistake, but it was the same every time (just under 2 revolutions of drive shaft to yield 1 tire rotation). Any insight on this would be appreciated.