I just acquired a 1960 Oldsmobile differential as part of a parts deal. Seems like it's in pretty good shape. Does anyone have any info or know where I can go for info on it. I did a search on here and on the net, but no dice. I would like to know the gear ratio and what years these type of rears were in use on Olds. Plan on using it behind a relatively stock 350/350 combo. I want to make sure it will be fine. So far I found they were behind 371 blocks(265hp) and 395 blocks(315hp). The drive train is for my 31 sedan. Any help is greatly appreciated. Thanks!
Like the Pontiac of the time, they were pretty strong. Both the Pontiac and Olds are basucally the same part and all parts that I know of interchange. They came with either 29 or 31 spline axles. The 29's arent very strong. While I never broke one, when I went to a 31 spline posi in my 56, the axles were twisted almost two splines...didn't break...! The one I had in my 56, 210 sedan and also had one on my Pro Gas Anglia. Never hurt either. There were two case configurations, a two rib and a three rib. Obviously the three rib being the stronger one. These ribs are big obvious things that go from the flange area to near the pinion. Either will work fine in a mostly stock 350. Go much above about 375 horse...go to the three rib case.... There used to be only the Dana type posi. But that died and then there was only the Eaton posi unit. Not sure what's available now. A friend has one that he's looking into parts for. Apparently someone is making gears for them again, so different gear ratios but just the 3.23's and 3.55's should be available. I ran 3.90's in my 56. most of the time but also had 3.73 and 4.11 each for a while. I normally ran 5.38's in my Anglia, but had other ratios for that too (4.88, 5.13, 5.86). Look harder, there are parts by the larger gear, axle guys out there. Mike
Those Olds/Pontiac rears were very popular with drag racers in the day so they're plenty beefy. The outer bearings are the same as later 9" Ford so they're not hard to source. 5 on 5" bolt circle and originally had left-handed studs on the driver's side. Seems to me that '60 rear is going to be way too wide for a hot rod. From the '60 Olds factory manual.
Those rear ends are HEAVY to say the least. And they are wider than most, but strong is putting it mildly. You can always have them narrowed.
anything you want or need for that is at Fabcraft in Texas. Tell Brad duerst that dave from Powell told you he can help you. check out his web site also. 57 to 64 pontiac and olds 3rd members are the same. 63 to 64 the pinion bearing is smaller and that was the only change. I have a 57 poncho housing in my 55 with a 60 pontiac posi with mark williams axels and stell main caps for the third member. Mark williams sells lots of that early 0lds pncho stuff also.
Thanks for the help fellas! Unfortunately it seems like the rear I obtained is a Chevy not an Olds. Awesome info though! Thanks once again!
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