Help identifying rear

Discussion in 'Got gears?' started by Beamer, Sep 11, 2004.

  1. Beamer

    Beamer Suncoupes Rule !!!

    My origonal post sort of got lost with the hacker problems.

    Needless to say, I am happy to have the board back up, thanks for all the effort doing so.

    Here are some pics of the rear that was in my parts car that I am trying to figure out what it is for usage and/or selling. It has 3.90 gears and posi, but I do not want that tall of gears for my setup. I am looking for a 3.42 gear/posi combo to put in my Suncoupe. I am thinking from what I have searched through the internet that this may be a Chevrolet rear. It does have C-clips vice bolt in axles. What I could decipher on ID stampings looked like "C K C". I would like to find out if the carrier will work in my car and then just fine my gears desired.

    Front of diff... Rear cover... And gears...

    The part number on the ring gear is "39 10 GM 265 J A"

    I was asked in an old post for the part number on the posi assbly, which suggested it was on the opposite side of the ring gear. I saw nothing there at all for part numbers. I started to take it apart, removing the pin, but could not figure out how to get the spring out of the way to get the C-clips out.

    Any help is very much appreciated.


    Attached Files:

  2. GStage1

    GStage1 Always looking for parts!

    First, you have a Chevy rear, CKC is plant production code. Last letter indicates Chevy. Secondly, someone welded in a spacer plate to a 2 series carrier. You can see the welds in your pic. Third, you really don't want to use that carrier since someone "modified" it. It may be ok for street but I would not use it on the strip.

    Lastly, you do not need to remove the "S" spring. Once you remove the 5/16" pinion shaft retainer screw, slide out the shaft and have an assistant press on the axle shafts moving them towards the center. Make sure brake drums are removed. Now, use a screwdriver to spin/rotate the C-clips off the axle. Repeat the process for the other axle. That's all there is to it!
  3. projectman

    projectman Well-Known Member

    Question for George

    Hey George,
    I've been to your website many times and find it very informative.
    I had a question
    If Mike doesn't mind.. I think its on-topic with identifying rears.
    I too am looking for the same thing.

    What is the best harvest candidate for an 8.5 upgrade to my 65 Skylark?
    Your site has much to offer, but I still don't feel like I have a handle on it.

    This Saturday I hope to combine a trip to the get-together in Harrisburg PA with a stop at a U-pull it yard along the way.
    If I were to find the "perfect" rear end it would be any turbo regal, or better still, a GN, to yield a 8.5 inch 3 series posi 28 spline rear end with 3.42 gears.

    But since that isn't likely...
    I would look for a 72-ish to 76-ish leMans or Skylark peg-leg 28 spline and then go posi-hunting in the big cars you suggest on your site. Maybe find a one-piece driveshaft while I'm there. I've heard a good source of posi's and 3.42 gears are pre 1990 chevy 1/2 ton trucks.

    Am I close to the mark?

    The main reason I am shooting for the 3.42s is I have a complete GN powerplant from intercooler to BRF tranny (in the dusty corner of the garage), and I would like to duplicate the driveline as well.

  4. GStage1

    GStage1 Always looking for parts!

    Your best source for the corporate 8.5 are the 71-2 Cutlass and Skylark models. They are called corporate because GM used the 8.5 center section from 71-89. Get the 8.5 housing and then you can get the posi unit w/gears from any GM car/van/truck with the 8.5 center. My best efforts have been with the 80-89 GM full size wagons. Some of them have tow packages which usually include 3.08-3.42 gears and a posi.

    Later models 73-77 A-bodies and 78-87 G-bodies will not have the correct rears so don't waste your time looking at those axle housings.
  5. projectman

    projectman Well-Known Member

    Now I got it! You've saved me a great deal of time looking under cars this weekend.

    All I have to do is get the three foot section of fence pipe for pinion nut leverage. :laugh:
  6. Beamer

    Beamer Suncoupes Rule !!!

    Thanks George for the answers.

    I intend to use the car for weekend cruising and very occasionally, putting it on a track to feel the acceleration and to see how it does. I do not plan to drag much at all.

    Do you think it will handle this kind of use? Is the welds what worries you? Or the point that it is a series 2 carrier? Are they weaker possibly?

    Thanks again,
  7. GStage1

    GStage1 Always looking for parts!

    Well, you will need more than a 3 ft pipe, you will need to use something to prevent the pinion yoke from turning. I use an old piece of bed frame, hardened steel L-channel. I bolt it to the pinion yoke and let it contact the floor pan before trying to break the pinion nut loose. Works every time!

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