Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

12 bolt or 14SF?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Emmettology 101, Oct 21, 2000.

  1. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    I currently have a 12 bolt with 4.10's in my Jimmy, but I also have a 14SF that I can install. I am going down in gears to a 4.56 and was wondering if I should swap in the 14 or just stay with the 12?
    Is there that much strength difference between the tow?

    The 14's ring gear is 5/8" bigger than the 12 and the 14 has 33 splines compared to the 30 of the 12.

    I will be buying gears for one of these soon, but not sure which. If I go with the 12, i will be putting a Mini Spool in it along with the gears, but there is no mini spool avaiable for the 14. Actually, the only locker I have seen avaiable for the 14 is an ARB, and that is too expensive for my blood.
    I know I can get the gears for the 14 really cheap and the install kit kit also, but the I would have to send out the axles and have them filled and drilled to 6 lug and I would have to do a rear disc setup right away.
    The 14 has a Gov-lok, but I wuld rather be locked.

    If I stayed withthe 12, I could buy gears and a spool and drop them in and go. Then downb the road I could do the brakes.
    But if I went 14, I would have to live with the Gov-lok and then get the axles redrilled and I would have to put discs on right away since this one I have has the large drum brakes that will not work with 15" wheels.

    ANy opinions?

    Or one last opyion would be to stick witht he 12, swap in the gears and then save up for a FF kit and then get a full spool, but that wouldn't be until Feb or so..

    ANd one last thing, a 14FF is out of the question.

    Thanks

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  2. Chris Demartini

    Chris Demartini 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    2,406
    Likes Received:
    1
    Location:
    Dumont NJ 07628
    <font color=blue>I would go with the 14 sf if you have decided against a 14 ff. You can get a detroit c-locker for it, and I belive you can get a lock-right too. I have a 14ff and when I got it, it had the huge 1 ton brakes. My 15" wheels fit over them with room to spare. It all depends on the backspacing. Why do you have to fill and re-drill the 8 lug shafts? Just get 6 lug ones, they're not much. Just out of curiousity, why dont you want a 14ff?</font color=blue>
     
  3. nyyef

    nyyef 1/2 ton status

    Joined:
    May 16, 2000
    Posts:
    479
    Likes Received:
    0
    Location:
    Saudi Arabia
    i was wondering the same, why not a ff? i would save the money keep the 12. otherwise go all out with a ff. i dont see the point of a 14sf, if you want to upgrade a 12.

    Knife.
    knife.coloradok5.com
     
  4. AJMBLAZER

    AJMBLAZER Better to be lucky than good. Premium Member

    Joined:
    May 18, 2000
    Posts:
    22,792
    Likes Received:
    100
    Location:
    Paducah, KY
    Most references to 12 bolt strength I have seen rate them as only marginally stronger than a 10 bolt. The most generous one, by far, said 30% stronger than a 28 spline 10 bolt. The usual number for the 14SF is 75% stronger than a 10 bolt, and that they are good for tires up to about 38". I am in the same boat as you, am not running HUGE tires, don't want to either, like my 6 lugs, and don't like loosing all that ground clearance to a 14FF. I just lucked out and found a 6 lug 14SF. Hope this helps.

    1992 Blazer Sport, 350 TBI, 4L60, 3" Flowmaster, K&N, 3" Rancho, 285/75R16 on 16x8 Baja's[​IMG]
     
  5. 6.2Blazer

    6.2Blazer 1/2 ton status

    Joined:
    Feb 24, 2000
    Posts:
    4,675
    Likes Received:
    26
    Location:
    Ohio
    I think the s.f. 14 bolt would be substantially stronger than the 12 bolt and there are other locker choices beside just the ARB. Since the 14 already has the Gov-Lok, you would obviously have to change the whole carrier out even for the lock-rite. Also, are you sure the 15" wheels won't fit on the rear with the current brakes (I'm curious because I'm considering the swap also). For changing to 6 lug, Moser engineering will supposedly re-drill both the axleshafts and drums for around $80.
     
  6. Hey mike did you try that 15" 8 lug wheel you bought to see if it would fit?I don't want to goto a 14 bolt ff either,the whole idea of runing bigger tires is more clearence and the 14 bolt ff takes alot of it away.I'm going to try a dana 60 rear,they have the best gear and locker options out there.

    IF IT AINT BIG IT AINT BAD!!!!!!
     
  7. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    Well with the right back spaing maybe they will fit, I haven't lined them up yet.
    Right now the axle is sitting with a 16.5 rim and a 16" rim(the way I got it). The 16" rim has minimal clearance(not even a pinky-fingers width), but has a stock-like backspacing. I imagine that if you were to use a 3.5" or so back spacing it may work.
    I will be trying that wheel that I showed you on the 14 bolt within the next couple of days( the 15x10 white Bart rim that was in the back of my truck when I met you) i will let you know what type of clearence it had.
    I was told by more than one person on the Pirate board that you can run 15's on a 60 and 14 bolt with 3.5" backspacing or less(one person saw a 4" BS once, but said a lot of grinding was done). I also received a comment that someone was using 15" rims with the large brakes on a 14SF with no problems, they said I just have to watch what BS I run.

    I'll let you know on the 15" wheel fitment!

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  8. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    I should be trying it within the next couple of days!

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  9. Thanks,let me know how it goes.I think I would use the 14 bolt sf if I were you.If not let me know if you want to sell it!!LOL I need a 4:10 8 lug rear.I would rather run the 14 bolt sf myself.

    IF IT AINT BIG IT AINT BAD!!!!!!
     
  10. bigdaddy89

    bigdaddy89 1/2 ton status

    Joined:
    May 18, 2000
    Posts:
    422
    Likes Received:
    0
    Location:
    Phx, Az
    Mike,

    Lockright has a locker available for the 14 bolt. It is the the no-slip. They are made super strong also.
     
  11. Stephen

    Stephen 1/2 ton status Moderator Vendor

    Joined:
    Sep 15, 2000
    Posts:
    4,227
    Likes Received:
    142
    Location:
    Carbondale Colorado
    Emmet, I would go for the 14SF with 6 lug axles, and get the disc brakes and a detroit. Whichever way you go I would stay away from the spool option, they are grumpy on the street, no matter what they say in the mags. We've run a full spool in our stock car, and you can't even roll the darn thing around on a hard surface. I think you would be ahead in strength far enough to abandon the 12 since you have the axle. One thing to watch is the width of the housing. I know some of the trucks got a wider rear in the IFS years, so an earlier version might be narrower. I don't have width info on all of them.
    SW
     
  12. Oblin Goblin

    Oblin Goblin 1/2 ton status

    Joined:
    Apr 30, 2000
    Posts:
    205
    Likes Received:
    0
    Location:
    Davis, CA
    Will the brakes from a 10 bolt bolt to a 14 bolt sf?
     
  13. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    Not sure, I know I have never tried it. Anyone else??

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  14. Emmettology 101

    Emmettology 101 3/4 ton status

    Joined:
    May 9, 2000
    Posts:
    8,126
    Likes Received:
    0
    Location:
    FL
    Not sure, I know I have never tried it. Anyone else??

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     

Share This Page