What rear end to use ?

Discussion in 'Got gears?' started by mkeeler, Feb 15, 2011.

  1. mkeeler

    mkeeler Old car guy

    I have a 1969 Buick GS 400 4sp, I am restoring. I have an 10 Bolt 8.2 open rear with a 2.93(?) in it now. I know a prior owner replaced the original with this. I have no idea what it came out of. I can't match the axle stamping with any GM rear end (GAC 1301). I want to swap in a posi.
    I am looking for a middle of the roader gear. 3.42-3.55.posi .
    Would I be better getting an Auburn or Eaton posi unit with a set of gears, or try and find a complete 8.2,8.5, or a 12 Bolt from Drum to Drum for an easy swap in?
    I have also seen references to BOP rear swaps. Anybody know of a site or article that give a crossover table. I have a Hollander manual but it is very nondefinitive on the 68-69 Buick A body rear end,and what else will fit.
    My problem is I can't seem to find out what GM rears are a direct swap. I have access to a 67 GTO posi drum to drum, but I don't think it will fit.
    Anybody have any guidance or suggestions
    Thanx for any help.
    MIke
     
    Last edited: Feb 15, 2011
  2. Steve Craig

    Steve Craig Gold Level Contributor

  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"


    You say the rear was previously replaced. Are you sure it is an 8.2? Post some pictures of the rear cover.
     
  4. mkeeler

    mkeeler Old car guy

    Thanx for the reply,
    Will post some pics today
    Thanx Mike




     
  5. mkeeler

    mkeeler Old car guy

    Steve
    I am a new guy to the site and am trying to find my way around. Where can I find George's article on the site. I used the search engine and came up blank.
    Thanx for the tip MIke






     
  6. Steve Craig

    Steve Craig Gold Level Contributor

    Double click on the address I posted.
    Site will have enough information to make you an instant expert.
    Search through it & you will find the article on 8.2 vs. 8.5 rears.
     
  7. monzaz

    monzaz Jim

    Your 67 GTO rear will be a DIRECT bolt in replacement.
    1967-1970 Buick Skylark, Custom Deluxe, GS... etc. OLDsmobile Cutlass, sx, 442 or Pontiac GTO TEMPEST LEMANS 69-70 GRand Prix will be a direct replacement
    1971-1972 Pontiac Tempest, Lemans, GTO, Grand prix is also direct bolt in with NO MODS.

    1971 1972 Olds Cutlass, 442 and Buick Skylark, GS will bolt into your 1969 Skylark BUT you will need to get a shorter drive shaft ...BUT that is all you will need.

    1968-1972 Chevy chevelle elcamino Monte carlo 10 bolt or 12 bolt will also fit with a u-joint conversion joint found at any auto parts store.

    chevy to buick conversion joint precision 372 / neapco 3-3130 / spicer 5-3022X

    Hope this info helps.... BEST to post your rear diff cover pictures put a few different ones up at different angles and we will ID it first so we know what parts are available for the rear at hand.

    JIm
    J D Race
     
  8. GStage1

    GStage1 Always looking for parts!

  9. mkeeler

    mkeeler Old car guy

    Thanx for the quick reply.
    Very informative and to the point. I can't thank ypu enough. I have to post some pics of some of my old cars that I have. They span GM to Mopar to AMC. They were just cars that I found by accident or were offered to me. I don't know if I can afford to fix all of them but they are great to look at and remenisce about. I just retired and I am going to spend my time tinkering with them. I have a 67 GS conv I did 25 yrs ago. Still runs great and never saw the rear of a rice rocket. I have been storing these things for 15-20 yrs.
    You guys are great and I respect all of the advice given to me. In the mean time I will get some pics of the 67 on my membership. The 69 GS 400 4 sp I found by accident online in Tennessee. It was under a house in a basement garage. One owner (female mother) passed on to the son. Matching #'s block 99% rust free. Ran but had 3 bad pistons. A little machine shop work, no overbore and fired right up. No exhaust just Buick Thunder.
    Thanx for all your input
    Mike













     
  10. mkeeler

    mkeeler Old car guy

    Thanx for the quick reply.
    Very informative and to the point. I can't thank ypu enough. I have to post some pics of some of my old cars that I have. They span GM to Mopar to AMC. They were just cars that I found by accident or were offered to me. I don't know if I can afford to fix all of them but they are great to look at and remenisce about. I just retired and I am going to spend my time tinkering with them. I have a 67 GS conv I did 25 yrs ago. Still runs great and never saw the rear of a rice rocket. I have been storing these things for 15-20 yrs.
    You guys are great and I respect all of the advice given to me. In the mean time I will get some pics of the 67 on my membership. The 69 GS 400 4 sp I found by accident online in Tennessee. It was under a house in a basement garage. One owner (female mother) passed on to the son. Matching #'s block 99% rust free. Ran but had 3 bad pistons. A little machine shop work, no overbore and fired right up. No exhaust just Buick Thunder.
    Thanx for all your input
    Mike













     
  11. mkeeler

    mkeeler Old car guy

    Here are some pixs of the rear end. I now think it is an 8.5











     

    Attached Files:

  12. GStage1

    GStage1 Always looking for parts!

    You have an 8.2" rear with a non-posi carrier.

    Talk to Jim (Monzaz) what is the best solution for your set-up....definitely need to add a posi carrier.
     
  13. mkeeler

    mkeeler Old car guy

    George
    Thanx for your help. I am going to give George a call.
    Mike




     
  14. painekiller

    painekiller Well-Known Member

    looks like an 8.2 chevy rearend
     
  15. monzaz

    monzaz Jim

    Right on. Chevy 8.2 10 bolt. 28 spline axles c-clip type.
     
  16. mkeeler

    mkeeler Old car guy

    Thanx for youe oberservation and your reply. Every bit helps. Mike




    Thanx for the observation
     
  17. mkeeler

    mkeeler Old car guy

    Doug
    I have the same color on my GS 400 4 Sp.Any place on the net with a decent pic that shows that color on a GS,. I am up in the air about the color.
    Mike








     
  18. Matt Ennis

    Matt Ennis Well-Known Member

    How about a 67 Pontiac Catalina?
     
  19. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Matt Ennis likes this.
  20. Matt Ennis

    Matt Ennis Well-Known Member


    Man those rear ends are getting pretty tough to find. I've seen a lot of custom made 9" ford rear ends that are going for pretty cheap made for the a body. What do you think about those?
     

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