Register now to get rid of these ads!

Technical 12 bolt rearend info please

Discussion in 'The Hokey Ass Message Board' started by olscrounger, Oct 11, 2020.

  1. olscrounger
    Joined: Feb 23, 2008
    Posts: 4,516

    olscrounger
    ALLIANCE MEMBER

    My friend just drug home a bunch of stuff a guy gave him. This stuff came from a 70 nova SS 4 spd he had. The rearend is a 12 bolt with the spring pads like a Camaro and Nova have and measures 60" wheel mt to wheel mt. I have a 69 Camaro 12 bolt in our 55 we put in 25 years ago with same dimensions as I recall. I'm interested in the rearend but don't know the value and want to be fair. Also a std bore 3999289 454 block assy (old) with a set of new 30 over pistons rods etc and bell housing clutch flywheel etc.
    Just looking for approx value and trying to help him figure out what he has or he will get antsy and haul it to the dump. Thank you
     
    Last edited: Oct 11, 2020
    lothiandon1940 and OLSKOOL57 like this.
  2. What's inside the 12 bolt? Makes a big difference.
     
  3. olscrounger
    Joined: Feb 23, 2008
    Posts: 4,516

    olscrounger
    ALLIANCE MEMBER

    Not sure--It's a long way from here--guess I could get him to remove the rear cover. Just redid the one in wife's 55-it is a posi and all new inside now.
     
    lothiandon1940 and OLSKOOL57 like this.
  4. 4speed411
    Joined: Jun 8, 2013
    Posts: 325

    4speed411
    Member

    $1000 is average camaro / nova 12 bolt..more if factory steep geared
     

  5. olscrounger
    Joined: Feb 23, 2008
    Posts: 4,516

    olscrounger
    ALLIANCE MEMBER

  6. How about a 2.73 open or a bare housing?
     
  7. lostone
    Joined: Oct 13, 2013
    Posts: 2,004

    lostone
    Member
    from kansas

    sounds high if its just a open diff/nothing special 12 bolt.
     
  8. Sounds high

    posi tears up here 12 bolt go for $500 give or take.

    unless it’s something special, it’s not really special.

    $1000 bucks sounds high
     
  9. $1000-$1200 For a first gen Camaro is about right, 10 bolts every where and cheap...
    $300 -500 for a truck 12 bolt is about right depending on whats in it.
     
    lumpy 63 likes this.
  10. I realize that car housings are different dimensionally, but are the carriers and ring and pinions the same from car to truck?


    Sent from my iPhone using The H.A.M.B. mobile app
     
  11. olscrounger
    Joined: Feb 23, 2008
    Posts: 4,516

    olscrounger
    ALLIANCE MEMBER

    Thanks all-I know years ago it was not easy to find a Camaro or early Nova 60" 12 bolt--lots of others out there though. Trying to help him decode with numbers-all we know is that it came out of a 70 Nova thus far-60.25 wheel mt to wheel mt--will figure it out-like the one in wife's 55 that that been there for 25 yrs-had it redone a while back-just looked it's a 3:55 posi-makes two nice black streaks too.
     
    Last edited: Oct 11, 2020
    lumpy 63 and 1933_willys_77 like this.
  12. 31Apickup
    Joined: Nov 8, 2005
    Posts: 2,914

    31Apickup
    Member

    olscrounger likes this.
  13. Budget36
    Joined: Nov 29, 2014
    Posts: 8,419

    Budget36
    ALLIANCE MEMBER

    Pretty sure the car and truck are different. I have a 12 bolt rear from a 63 GMC and when looking into either ring and pinions or carriers maybe, been years, “fits all 12 bolts from -whatever year range- except trucks”. With the carriers it might just be because of the axle splines, I really don’t know
     
  14. Budget36
    Joined: Nov 29, 2014
    Posts: 8,419

    Budget36
    ALLIANCE MEMBER

    At 1000-1200 you’re getting close to the price of new aftermarket, huh?
     
  15. buffaloracer
    Joined: Aug 22, 2004
    Posts: 807

    buffaloracer
    Member
    from kansas

    The truck and car differentials are different, close in some ways but different.
     
  16. 41rodderz
    Joined: Sep 27, 2010
    Posts: 6,049

    41rodderz
    Member
    from Oregon

    No . I have seen from $2,100 low to $3,400 for complete refurbished 12 bolts. Used from 1,600 and up. Google and companies come up with refurbished for those prices .
     
  17. 41rodderz
    Joined: Sep 27, 2010
    Posts: 6,049

    41rodderz
    Member
    from Oregon

    Even if a high numerical gear and non posi , that can be changed.
     
  18. Budget36
    Joined: Nov 29, 2014
    Posts: 8,419

    Budget36
    ALLIANCE MEMBER


    Interesting, I had Currie make me a 9 inch with drum brakes, all I had to do was put on whatever brackets were needed, and the drop in. Was around 1100 hundred to me (8-9 years ago) maybe prices have really shot up?
     
  19. 56sedandelivery
    Joined: Nov 21, 2006
    Posts: 6,695

    56sedandelivery
    Member Emeritus

    ^^^That's pretty much the case around here^^^. First of all, they're not making them anymore, so finding a Nova/Camaro 12 bolt is next to impossible. The only one more difficult to find is for the 66-67 Nova's. Secondly, to have the correct mounts AND numbers is critical to restorers. I've seen them on Craig's list for $2500.00-$3000.00, and they don't seem to last very long. I am Butch/56sedandelivery.
     
    lumpy 63 and olscrounger like this.
  20. Budget36
    Joined: Nov 29, 2014
    Posts: 8,419

    Budget36
    ALLIANCE MEMBER

    Ya, I could see that for a restore thing, a guy offered me 250 bucks for the riveted on plate for my TH400 from a 70 vette.
     
  21. Stueeee
    Joined: Oct 21, 2015
    Posts: 261

    Stueeee
    Member
    from Kent, UK

    Ring and pinion is different on car and truck. Both rings are the same size and will bolt up to either differential, but the pinion is a much larger diameter behind the gear on the car version where the pinion end bearing goes. the pinion centre distance is different on the car and truck ring and pinion sets, meaning that the hypoid offset is also different, meaning that the car and truck R & P sets can't be made to interchange even if the bearing size issue is solved by machining.
     
    Last edited: Oct 12, 2020
  22. 59Apachegail
    Joined: Apr 30, 2011
    Posts: 1,395

    59Apachegail
    Member
    from New York

    Something for you to consider... Depending on the condition of the rear you can easily spend another $1200 to buy new internals. That is if the axle welds are not leaking.
     
    olscrounger likes this.
  23. olscrounger
    Joined: Feb 23, 2008
    Posts: 4,516

    olscrounger
    ALLIANCE MEMBER

    Yep--mine was $1150 to redo last year. Needed it after 80,000 miles and a lot of passes at the drags-pd $25 for it in 1984
    Just looked at receipt--3:42 new gears, eaton posi new axles and bearings
     
    Last edited: Oct 12, 2020
    lothiandon1940 and Budget36 like this.
  24. I priced one up at Moser, after seeing this thread..Round figures $2500 with better axles. Still , 50 % of new, is top dollar, in my opinion .That is, if it's not all rust pitted from up north.
    Problem with used, is lots of folks don't know what they're selling . Another group is just downright dishonest.
    At least with new, you put it and forget it for a few years
     
    Budget36 likes this.
  25. partsdawg
    Joined: Feb 12, 2006
    Posts: 3,148

    partsdawg
    ALLIANCE MEMBER
    from Minnesota

    Sold one a month ago with 3:36 gears and it was a posi. $1200 and the buyer drove from Oklahoma to Minnesota. Had clear stamped numbers and it was going under a restoration.
     
  26. wheeldog57
    Joined: Dec 6, 2013
    Posts: 2,305

    wheeldog57
    Member

    As some stated above those Nova 12 bolts are rare and expensive. I could never afford one when I had Novas.
     
  27. olscrounger
    Joined: Feb 23, 2008
    Posts: 4,516

    olscrounger
    ALLIANCE MEMBER

    Thus far it appears to be a 3;36 posi by the numbers--very clean- no rust etc--May snag it as it is the perfect rear for a 55. He is gonna open it up and send me pics etc-I'm good at $1000-1200-as said it was $1150 to rebuild mine last year so $2200 all in is good with me.
     
    lothiandon1940 likes this.
  28. Chevy55
    Joined: Nov 6, 2008
    Posts: 409

    Chevy55
    Member
    from Nebraska

    3.36 sounds like a 10 bolt gear. Should be 3.31 in a 12 bolt. I would double check before I spent the money.
     
    Black Panther likes this.

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.