ice man Posted August 25, 2023 Share Posted August 25, 2023 I purchased a second GS-340 many years ago but never paid a lot of attention to things underneath. Now, I have noticed it's a limited slip rear end. After checking my option chart for '67 , limited slip was not an option for those vehicles. Now I'm wondering what was installed in place of the original? Here is what I've determined so far. First off, I've cleaned the entire right axle tube to try to find any readable code numbers and have found nothing. If there were, they got destroyed by jack stands. The cast body has 10 bolts and the 2 larger chunks at 5 &7 indicating it's an 8.5". The cover is oval with the large scalloped recesses at 9 and 3, which was used on 8.2's. The cover also has small arrow protrusions outward at 6and 12 and the bottom bolts are 3" on center. On the casting is the cast clock (indicating 1 and pointer at 6) followed by 35. Further down the case is #1235187 or maybe the 8 is a 9. Continuing around the bottom going up is CFO or O is a D. There is also three big 1" A's. One on top and one by each axle tube. Axle tubes are 3" dia. Pinion nut is 1-1/4", Ring gear has # 2344746--41-16 GMC W and held on with 10 hex bolts. I didn't count teeth or measure ring gear. I just would like to know what the hell vehicle this rear came out of. Any info you folks can supply would be much appreciated. Oh, it also has what looks like original coil spring perches. Thanks Link to comment Share on other sites More sharing options...
Brad Conley Posted August 26, 2023 Share Posted August 26, 2023 Pictures are worth a 1000 words but I am positive positraction was available for GS's in 1967. 1 Link to comment Share on other sites More sharing options...
ice man Posted August 27, 2023 Author Share Posted August 27, 2023 Brad: Posi was available in '67 but not for the GS-340. As far as pictures, I'm lucky to have gotten the write-up posted " OLD SCHOOL" It's definitely a 10 bolt for sure, just don't know out of what. When I measured between the backing plates I came up with 55-1/4 inches. Maybe I'm reading too much into this but it would be nice to know if it's Buick, Pontiac, Olds, Chevy or GMC small truck as some trucks had coil springs. Link to comment Share on other sites More sharing options...
JohnD1956 Posted August 27, 2023 Share Posted August 27, 2023 Buicks had no C clips to hold the axles in the rear. I think all the other A bodies did, but I am open to correction on that. 1 Link to comment Share on other sites More sharing options...
EmTee Posted August 28, 2023 Share Posted August 28, 2023 A photo of the rear cover would also be helpful. Link to comment Share on other sites More sharing options...
ice man Posted August 28, 2023 Author Share Posted August 28, 2023 John, no C-clips on Buicks is a step in the right direction. Pictures would help if I knew how to do it. The cover is scalloped at the 3 and 9 o-clock positions which from what I've read, indicates an 8.2. My housing indicates an 8.5 because of those extra square chunks in the casting at the 5 and 7 o-clock positions. I assume then that an 8.2 cover can bolt to an 8.5 differential?? I'll work on pictures but thanks so far. Tom G Link to comment Share on other sites More sharing options...
ice man Posted August 28, 2023 Author Share Posted August 28, 2023 I took several pictures of my differential with my I-phone and thought maybe there was an easier way to post pictures up here thru my phone. Well, can anyone tell me why I can sign in on my computer to post but when I try to sign in from my phone I can't, using the same username and password?? Tom G Link to comment Share on other sites More sharing options...
ice man Posted August 31, 2023 Author Share Posted August 31, 2023 Link to comment Share on other sites More sharing options...
ice man Posted August 31, 2023 Author Share Posted August 31, 2023 look above. Here you go, this is the best I can do, but not done by me. I hope this helps someone ID this thing. Tom G Link to comment Share on other sites More sharing options...
EmTee Posted September 1, 2023 Share Posted September 1, 2023 Looks like the same cover... Link to comment Share on other sites More sharing options...
ice man Posted September 7, 2023 Author Share Posted September 7, 2023 That doesn't help much. My cover doesn't have that rectangular notch, it has a small pointed protrusion at the 6 & 12 positions. The rear end is a 10 bolt 8.5, not 8.2. Link to comment Share on other sites More sharing options...
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