How much is it worth

Discussion in 'Got gears?' started by Dale G, Nov 30, 2017.

  1. Dale G

    Dale G Active Member

    I did not know where else to post this question so I thought I would start here. You must forgive me because I am actually a Pontiac guy. When I bought my 65 GTO years ago it had a Buick rear end in it. After some research I got it narrowed down to a 68/69 GS/400 rear end with 3.36 limited slip gears. I decided to just leave it in there and did my restoration of the car and rebuilt the rear end, boy are those 507G bearings tough to find. After rebuilding the rear end I decided to put a 5 speed overdrive transmission in it. Once I got it back on the road and drove it for a while I realized the 3.36 gears are to high and they have me running at to low of an RPM on the highway. So instead of tearing back into this rear end and replacing the gears I have decided to sell it and put a new aftermarket rear in it with better gears. I won't know for sure exactly what it is until I take it off and find the numbers, which I believe are on the top of the axle tube. So I was wondering what a freshly rebuilt 68/69 Buick rear end is worth with 3.36 limited slip gears in it? I also have the drum brakes but they weren't restored. This is the rear that was only available for a couple of years and used the larger 507G bearings. You must forgive the pictures because they are from before I restored the car when I was trying to figure out what the rear end was. All I knew was that it wasn't a Pontiac rear end. I did include one picture from after the restoration.

    Thanks for the help, again,

    P1030486 - Copy.JPG P1030491 - Copy.JPG P1030492 - Copy.JPG P1030497 - Copy.JPG P1030500 - Copy.JPG 20170701_113312 - Copy.jpg
  2. BrianTrick

    BrianTrick Brian Trick

    There was no 3:36 for that Buick rear. It is either a 3:23 or 3:42,in that range. The code is on the axle tube,facing down or forward. You have a clean one,so you should be able to find it.
    What rear or what ratio were you considering? Where are you located?
  3. rkammer

    rkammer '71 GS455 Arctic White

    Brian is right. Pontiac offered 3.36 ratio but, Buick only 3.23 or 3.42. If yours is truly a Pontiac rear, you can go as high as 3.70 and it's a bolt-in for your 3.36. That ratio would be good for your 2004R. If you want to go higher, you can go to a 4.11 if you install a spacer on the ring gear which is done often. But, in either case you don't really need to sell your entire axle.

    If your rear happens to really be a Buick, you can go with 3.73 or even 3.90 with just a ring and pinion change. All the above gear sets should be readily available.
  4. Dale G

    Dale G Active Member

    OK, so now I am really confused. When I bought the car it had this rear end in it. I know it is not a Pontiac because the casting of the center is different from a Pontiac, Pontiac had an additional fin that Buick and Oldsmobile did not have. When I researched it years ago when I bought the car people on a Buick forum helped me identify it as a Buick rear end. That was confirmed when I pulled the axles and the bearings were stamped 507G. As far as I know Buick is the only one that used these axles and they were 1968 to 1969. I thought it was a 3.36 because the previous owner gave me all of his receipts and there is a receipt for a 3.36 posi traction rear end and labor to install it.

    So I have a couple of questions for you guys; Where can I find the rear end codes without having to sand and destroy too much of my freshly painted axle? Is this a Buick rear end? Is it possible that someone could have put a 3.36 gear in a Buick rear end?

    I am planning on replacing this rear with a Strange S-60 rear end with 3.73 gears. The research I have done this ratio would work well with the .64 OD and my cam. I guess I could put 3.73 gears in this rear and save some money but I was wanting a little stronger rear end.

    Thanks for the help,
  5. rkammer

    rkammer '71 GS455 Arctic White

    Someone else will probably post with more info on the Pontiac vs. Buick question. As for replacing the axle with a Strange S-60, how much horsepower will you be running? The 8.2 rear should be sufficient for horsepower up to well over 400 unless you plan on serious racing with sticky tires.
  6. Dale G

    Dale G Active Member

    It is my understanding that there are no aftermarket or new parts available for this rear end with the bigger bearings, 507G, which means if I wanted to go to a 3.73 I would have to luck into a used one, no thanks.

    The other possibility is this might be out of a station wagon. I was thinking while I was eating my oatmeal, very deep thoughts, and the previous owner had station wagon springs under the back to raise it up so he could run 275 street slicks. It never occurred to me that the springs could have been part of the rear end when he bought it. I know that 3.36 gears were an option for the Riviera, is it possible they could have been for the station wagon as well, or, did the Riviera use this same rear end with the bigger bearings?

    My car is producing just a little under 500HP and 574Ft/Lbs torque. And no, it won't see any track time. If they made a 3.73 gear for this rear end I would probably keep it, I already have a lot of money invested in it.

    What I need is to find the codes on the axle tubes, I guess I will be ruining a new paint job:(

  7. rkammer

    rkammer '71 GS455 Arctic White

    Yes, the axle codes are needed to settle the question for good. There are parts available for the 8.2s. When I bought my GS several years ago it had (and still has) a Pontiac rear from a GTO with 3.55 gears. The posi was gone and I was able to source a new Eaton posi unit for it along with all the bearings and small parts to rebuild it. My engine dyno'd at 468 HP with over 550 ft. lb or torque and I've had no problems with the rebuilt rear end. Even had it to the track a couple of times but, I don't run drag tires any longer. Just lots of spirited street driving. I'll try to locate the name of the forum member that is the local expert on rear ends and post here.
  8. Dale G

    Dale G Active Member

    Thanks that would be nice. If I can't find the codes I am going to pull the back cover and that will be a definite way to figure this out.
  9. rkammer

    rkammer '71 GS455 Arctic White

    The rear end guru is MONZAS on this forum. If you could take a shot of the rear cover, a side view of the housing and a shot of the interior with the cover removed, he and others will be able to identify it. Just post it in the "GOT GEARS" forum.
  10. Dale G

    Dale G Active Member

    I will have to order a gasket and get it in before I remove the cover so I can make sure I get it back together before Monday. Thanks for the info and helping with this.
  11. BrianTrick

    BrianTrick Brian Trick

    You can get new 3:42’s and 3:64’s for that Buick rear.
    For what you are doing,a 71-72 8.5” 10-bolt,out of a 71-72 Skylark GS or 71-72 Cutlass/442 will be more than enough. They are a stout rear with plenty of parts and ratios available. You can get 3:08,3:23,3:42,3:55,3:73,3:90,4:10,etc.
    Something like that,from me,would be $1300.00 plus the freight. All new parts,ready to run.
  12. Dale G

    Dale G Active Member

    Thanks, I will definitely keep that in mind. A lot cheaper than a new aftermarket rear end. What would shipping be to Jackson, MO 63755, or are you close enough I could pick it up? Do you have the 3.64's for this rear end or know where I can get one? I guess 3.73's are not available for it?
    Thanks again,
  13. wkillgs

    wkillgs Gold Level Contributor

    You have the same casting numbers on yours as my '66 GS does, 1375689. It may have been used for other years too.
    Are the spring perches on the rear flat? And use a retainer plate to hold spring in place? If so, it's a 1966 rear.
    If the spring perch has a raised center that fits up into the spring, it's a 67 or later rear.

    Codes should be stamped into the drivers side axle tube somewhere between the center housing and spring perch, on the bottom side.

    Sportwagon used the large 507G too, 66-68. The 67 rear I have has different brackets, not sure about theother years.

    3.36 was std on 4 speed cars. Yukon and Motive offer gears sets for the early rears, 3.36, 3.55, 3.73. 3.90, 4.11. uses the same carrier (3.36-up).

    Value of yours? Might be a tough sell since there isn't much demand. The 8.5 is a better rear.
  14. Dale G

    Dale G Active Member

    So this is getting even more confusing. The springs have the retainer on them, which according to your information is a 66 or earlier. I found the codes. It has the circle X which confirms it is a posi unit. Then the date code has a "D" then a "5" then the last number is poorly stamped, it comes to a point like the top of a "4" or even a "7" or a "1" (which should be April 5 of some year, but what I can't tell). The axle code has an "L" then the next letter is hard to read. It comes to a point like that bottom of an "X", an upside down "V" or a "7" on its side. Needless to say I can't find anything on the internet that even comes close to this combination.

    Oh, and to make matters worse when I measured the width it has the wider width of the later years, unless I measured wrong.

    So how far back did Buick use the 507G bearings?

  15. BrianTrick

    BrianTrick Brian Trick

    I would ship it Fastenal,store to store. It would be about $150.00 to do that. I am in northwest Pennsylvania,so shipping is probably the better option.
    Let’s get a positive identification on what rear you have. If the rear came out of an earlier Sportwagon,you would have a few different options. If it is indeed a 68-69 Skylark/GS rear,then the only options for new gears are 3:42 and 3:64,which are made by FabCraft,in Texas. I think they are $475.00 for the set.
  16. Dale G

    Dale G Active Member

    Look at the above message I just sent. I did find some numbers but they make no sence to me.
  17. wkillgs

    wkillgs Gold Level Contributor

    1966 was the first year. 1965 used a different axle and RW507A wheel bearing.

    My notes say 61" drum-drum for a 66 rear.

    'LX' is the 66 code for 3.36 ratio with posi.

    I think we have a match!

    Next step would be to check the pn on the gears for a positive ID.
  18. Dale G

    Dale G Active Member

    The second number on the date still confuses me since it doesn't look like a "6" but I will look again. So you agree it is a 3.36 but what is it out of, a station wagon or a Skylark since I can't find reference to the 3.36 in any Buick other than the Riviera? Also, what am I looking for once I take the differential cover off? I know that there are numbers that can be used to identify the gear ratio, but is there anything else I need to look for? Also, I have disc brakes on it, what would be the flange measurement?
    Thanks for all of the help. So much for when someone told me it was out of a 68 GS.
  19. Dale G

    Dale G Active Member

    So I found another forum where someone was trying to identify a rear end in a 67 GS that had the "LX" code and he was told it was a 67 GS 3.36 posi rear end. Is it possible this could be a 67 rear end with the spring retainer mounts and the bigger 507G bearings?
  20. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    There are two numbers on the ring gear. Divide the smaller number into the larger to get the ratio. 41-11 would be 3.73. Monzaz is our rear expert. His website is He has pictures to help you ID rears.

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