9", or 12 Bolt?

Discussion in 'Got gears?' started by GRIMM, Aug 28, 2006.

?

Which differential would you prefer in a 3600 lb car with 700 hp?

  1. The Ford 9"

    42 vote(s)
    43.8%
  2. GM 12 Bolt

    54 vote(s)
    56.3%
  1. Nothingface5384

    Nothingface5384 Detail To Oil - Car Care

    in my opinion i would either stick with a 8.5 10bolt and beef it up with 33 splines or if you want to go ford go ford 8.8 as its more efficiant then the 9 , probly lighter... and its not that much weaker then the 9inch
     
  2. Keith Seymore

    Keith Seymore Well-Known Member

    I apologize for popping in unsolicited all the time, but -

    I have been running the same 8.5" ring gear 10 bolt for 28 years. Standard housing, welded tubes, Mark Williams spool and axles with C clip eliminators. 10.20's at 3950 lbs. And that's race only for the last 26 of those years (almost zero street use).

    I would recommend the 10 bolt, especially for a quick street car that is going to see occasional race use.

    [​IMG]
     
  3. GRIMM

    GRIMM Well-Known Member

    Well, i tried editing it to add options to the poll and to change the title, but i couldnt so i made another thread for it, hope nobody minds casting a vote again.

    thanks
     
  4. philip roitman

    philip roitman Well-Known Member

    My 1st choice was a 9 in Ford. Tried to find a 12 bolt cause it was easier,cheaper? I was amazed :Do No: Currie and moser do not make one for a 73? (only up to 72 :af: ) Ended up ordering a 9'' from moser (should be a bolt in :3gears: ) With a 389 rear and all the good stuff was $2150 inc. shipping! Hoping for the best and all. Ordered it last Thurs and it should be at John C's shop this week :TU:
     
  5. GRIMM

    GRIMM Well-Known Member

    what car is that going in?

    i can see if its the GS, because its an A body, but for a B-body they quoted me upwards of 3000 because it would have to be cutom made.
     
  6. 455regal

    455regal Well-Known Member

    Hi!
    I used a 9" from a lincoln versailles ( comes with disc brakes) It has 28 spline axels but currie or moser make 31 if you want I run 3.90 gears (trac loc) What I like is if I want to go on a long trip in 1 hour I install my 2.75 pot and I'm away!! Try that with a 12 bolt!! And I can get parts at any parts store!!!
    Just my 2 cents!!! Brad
     
  7. Hotrodgss1

    Hotrodgss1 Aiming High!

    If your looking to run your race car on the street, a 9" is the best way to go. One center housing can run a 4:11 spool set up while another one can have a 3:55 posi set up for the street. The combos are endless.
     
  8. staged67gspwr

    staged67gspwr "The Black Widow"


    Whats the problem with the upper arm mount,i wasnt aware of anything like that just curious??:Do No: :Do No:


    Thanks
     
  9. staged70

    staged70 RIP

    I am an old Ford racer and if you need any more convincing NASCAR uses 9". The combinations as mentioned are endless. Plus you can choose iron or aluminum third members. The 9 is basically bullet proof. WHy do so many racers use a 9 well ask them.
     
  10. monzaz

    monzaz Jim

    Here we go. NASCAR is NOT drag racing- It is endurance that is a bearing and heat issue. They use the 9" because Nascar tracks differ and gear swaps are easier to tailor to a particular track. The bigger ring is always the best choice in big circle track it bleeds off heat. In Drag racing a large ring gear is not as necessary. The 9" Nascar are FAR from stock. Are we comparing stock rears from the factory? We need to compare the rears APPLES TO APPLES...

    And if they are compared that way 12 bolt is the only way to go for all around strength.

    The FORD (10 bolt) 9" rear in stock form does NOT compare.

    LOOK at the up grades for the ford 9" The whole rear in nascar form is NOT one stock part. EVERYTHING IS REDESIGNED AND AFTERMARKET.

    WE are still using 12 bolt chevys in cars in stock form and they still do the job. All we need to do is c-clip elim it ... OLD school still holding up over time.

    Every rear diff offers something ...you need to figure out your particular NEEDS and pick the right rear.

    I do not dislike FORD 9", I just do not like them either...lol. :Do No: :Brow:

    I am not trying to chew your posy just the subject matter at hand...You just happen to be the one bring it up...lol. DO NOT TAKE THIS AS A personal bash AS IT IS NOT You are cool and can like what ever you want.:TU:

    I am GM through and through. USE WHAT YOUR MAMA GAVE YA :3gears:

    Have fun with the ever popular on going argument of 9" 12 bolt...

    Jim
     
  11. monzaz

    monzaz Jim

    I am working on that...lol. Jim
     
  12. RACEBUICKS

    RACEBUICKS Midwest Buick Mafia

    I vote 12 bolt

    I have a built 12 bolt and its seen 800 plus lbs of torque and over 800 HP every pass for like 1000 runs. The ring and pinion gave up is all and it was the old one from over 15 years worth of racing. I have since changed out the 411s and went to a 433 but not because it was broke :Brow:
     
  13. gusszgs

    gusszgs Well-Known Member

    Some good points here, good info.
    Wow, pretty old thread though......where is Grimm these days?? :bglasses:
     
  14. Here is another apples to oranges comparison.

    I have been racing in an entry level class at local dirt tracks (ovals). for the first 5 seasons I ran a chevy 10 bolt rear end. I could count on braking one axle each season.

    Then I stepped up and got a 9". I am going on the 6th season using this rear end with 1 broken axle.

    The axles are much larger in dia = stronger. They are easier to work on and changing gears takes an hour.

    They are heavier but if you want to spend some cash you get get all aluminum stuff (luckily my rules don't allow that).

    My buick (street car) currently has a 10 bolt but will eventually be upgraded to a 9". Currie is about an hour from me and I can pick up a set up with disc brakes under $1200 w/o third member (at least last time I checked).

    CD
     
  15. 2stg14spds

    2stg14spds Well-Known Member

    9" 3 teeth of the gears are in contact at all time makes them hard to beat for strenght
     
  16. monzaz

    monzaz Jim

    LOL... 2004 GTO has about 4-5 tooth contact...But it is the size of a fist...lol. try a 2.14 gear they have 4-6 teeth always in contact there are 21 teeth on the pinion and 47 on the ring...lol 7.5.

    Not enough for me to switch. Ford trac locks are garbage...I do not think ford EVER made a good posi from day one. AGAIN these are ALL just opinions BUT considering how many need rebuilding and how quick they eat them up.

    Even when Ford did copy the 8.5 and 12 bolt rear to make their 8.8 they GOOFED the posi AGAIN! used GLUE on material for the clutches...??? BUT then again so is CARBON FIBER... GLUE ON??? I have seen guys try to drag race carbon fiber posis and the material just gets ripped off the clutch it is glued too.

    oops sorry got of the subject...Boooo Ford I am back... lol. :idea2: :spank: :blast:
     

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