Hi Jim, I have just restored my '70 Buick GS 455 and it has a 10-bolt posi with 4.11 gears. I am wanting to put 3.42s in it but I am not sure the rear-end in it now is the original 8.2". I was told that a TRUE '70 rear-end was not designed to accept an aftermarket ring and pinion such as the 4.11 and my rear-end is probably from a '71 or later GM - which would be great. I have found a 3.42 ring and pinion for a 8.5" 10-bolt but I'm not sure how to tell if my rear-end is the 8.2" or the 8.5". I am hoping it has the 8.5" so I can purchase this 3.42 and make the swap. Any way to tell?? Thank You! Van McD
Thanks so much for the info Larry. The pictures helped me determine that I unfortunately have the 8.2". Was hoping for the 8.5 so I could get the 3.42 gears I found. Thanks again! Van
That picture should be revised as it is only 1968-1970 housing. the 1965-1967 look different in the center section casting. The 68-70 are nodular and very thick cast like in theat picture. the early ones have a much thinner cast center in the axle tube collar area. Both still have 1 lower webbing only. Plus both use the same yoke also. Jim
That is totally correct. 8.5 BUICK. The Olds 71 72 does NOT have the lower casting and has the traditional round 8.5 cover from 1973 -2008. Jim
I'm new to this site but stumbled upon this thread and think I might have found my answer. I have been trying to find informantion on a strange posi that I have been planning to sell. I wanted to find out where it originally came from before I listed it on ebay because I knew I would get all kinds of questions that I didn't have the answers to. I know that it is a 8.2" BOP with the drivers side carrier bearing being a larger diameter than the passenger side. It also has a factory GM 3.08 ring and pinion set as well. From this thread I gather that it is 68-70 Buick only but was it used in all Skylarks or just the GS models. How about the LeSabre? I know that the Electra and Wildcat used a larger rear but what did the LeSabre 350 or 400 cars use? Any info would be appreciated as I haven't been able to find much info on this thing. Most people think that I'm crazy when I mention it has two different size bearings. Thanks guys for your help.
68-70 Lesabre have the same center section 10 bolt 8.2 rear end guts as the skylark in the same years. So yes these are interchangeable guts. These years ONLY. As far as the Electra??? Not sure as of yet at this time. I think it is larger. CAsting number on the center section will help. Jim
This thread confirmed that this posi carrier is a 68-70 Buick. I already knew it was an 8.2" 10 bolt. Any idea what it is worth complete with a 3.08 ring and pinion? Works well, excellent pattern on gears and no noise.
Jim I have a 1975 Olds Omega with a 10 bolt 8.5 with 3.08 gears. What can You do as far as making this thing a Great Posi or even a decent LSD and keep my 3.08 gears?
