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12bolt w/ARB or 14bff w/Govlock?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by macg, Apr 20, 2006.

  1. macg

    macg Registered Member

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    I need to change axle ratios and currently have a 12bolt rear. I have a 14bff at the house ready to go but it has a govlock.

    If cost difference was not an issue, would you regear the 12bolt and add a selectable locker, or use the 14bff with the govlock.

    It's for a 78 k5, 350,350,203, 4" lift, 35" to 36" tires, light to moderate offroading.

    Thinking about weight, ground clearance, strength/reliability, and street manners.
     
  2. HarryH3

    HarryH3 1 ton status Author

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    14 bolt. I ripped the teeth off of 3 ring gears in 3 years running a 12 bolt and 35's. Besides, a Detroit Locker for the 14 bolt (and an open carrier) cost WAY less than the ARB for the 12 bolt. :cool1:
     
  3. 87BrnRsd

    87BrnRsd 1/2 ton status

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    Couldnt have said it better myself.
    -Harrison
     
  4. cbbr

    cbbr 1 ton status GMOTM Winner

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    X3.
     
  5. MTMike

    MTMike 1/2 ton status

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    X4.
     
  6. G-Force8

    G-Force8 1/2 ton status

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    X however many people are a member on CK5 that have made 12-bolt soup
     
  7. 94yukon

    94yukon 1/2 ton status

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    I broke 12blts never a 14blt yet u lose clearance and add weight plus the cost of different rims. I run a welded 14blt and love it. if you are using a light front at least u can make it home on the rear 14blt.
     
  8. G-Force8

    G-Force8 1/2 ton status

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    exactly 94yukon , that is probably how I'm going to start out with on my Suburban and Wagoneer. D44HD/Corp 10-bolt front and a FullFloat 14B rear. D60 fronts are just to costly for me right now and I just want to get these trucks out and have some fun....and at least I know if I have a prob with the front ( as long as the housing doesn't split or something!) The 14B will get me home.

    Even for you 'light wheelers' who think about keeping a 10 or 12-bolt rear and putting any money into them at all.........don't. Corporate 14-bolt rear axles are so plentiful and inexpesive its a no-brainer. Yes you lose some clearance,but the lower portion of the housing can be shaved quite a bit to get alot of it back. Yes the 14-bolt is heavier than the smaller bolt-wanna-be's but I think most will agree that it is well worth the trade off.

    Especially if you build a ferocious Rat to compensate and then some!
     
  9. MaxPF

    MaxPF 1/2 ton status

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    Well, lessee. A 12-bolt complete w/brakes weighs in at 180lbs or so. a 14bff tips the scales at about 580lbs (520 if you convert to disks). The 14bff drags the ground like a plow, and even shaved will have less clearance than the 12bolt. The added unsprung mass of the 14b makes for worse ride quality, and the added weight and internal drag will reduce gas mileage. Finally, if you keep tire sizes reasonable (35" or less) and drive with your brain and not your right foot, then you won't break the 12-bolt.

    OTOH, the 14 is uber-strong and reliable, and it is a full-floater. A 14b Detroit is fairly inexpensive compared to other axles. You don't really want to use a gov-lock. If you want big tires and/or you really like to flog the crap out of it, then this is for you. Don't forget that, in order to do it right you will need to convert your front to 8-lug hubs, along with their associated rotors, calipers, and backing plate. Otherwise, you will have a mix of 8-lug and 6-lug wheels on your truck, which will require two spare tires (one for each wheel pattern). It didn't take much cost analysis for me to figure out that a PROPER 14b swap was far from being as inexpensive as some would have you believe.
     
  10. HarryH3

    HarryH3 1 ton status Author

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    You just have to be a better shopper! :) When I converted my K5 to 8-lug, I bought an entire 3/4-ton pickup for $850. Swapped axles between it and my K5, then cleaned up the pickup, fixed a massive engine oil leak, and sold the pickup for $1,400. So I actually made $550 and got a 14 bolt FF and Dana 44HD with 4.10's in the process. :cool1:
     
  11. G-Force8

    G-Force8 1/2 ton status

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    good point HarryH3

    I recently came across a '73 chevy Suburban complete with the D44HD front/14-bolt rear and an all-gear NP205 case for $300. The body was rusted badly and the engine needed an alternator + the tranny was out but what was worth keeping on the truck could have been parted out for at least twice the purchase price of the truck.

    And usually the cost of doing an 8-lug conversion to match a swapped in 1-ton rear axle is more expensive than buying a 3/4-ton front outright. A 3/4 ton hub conversion done right which also includes re-gearing to match the rear is up near a thousand$$. 3/4 ton 10-bolt/D44 front axles usually go for around $200 or less complete and usually have 4.10 gears in them. When you factor in the cost of new ball-joints,rod ends,bearings,etc. to freshen an outright 3/4 T front axle up you are a little more than 1/3 the cost of doing the 8-lug conversion.......so yea, use your head.

    Plus, it sounds all good and dandy to say 35's are ok on stock 10/12-bolt front/rears but if you want any kind of performance you have to start thinking about lockers. Corporate 14-bolt detroit lockers are in the $400s while every other detroit for 10/12-bolts and most popular pigs are well over $500. Then alloy shafts and ring-gear swaps for the larger tires on the smaller axles ..........you're just throwing money at axles that limit your tire size and growing potential.

    A Dana60 rear is also a good choice. I have one in my sights for $100 that is off a Dodge 1-ton that can be easily made to fit.

    All-in all if a truck will see tires larger than 33" , in my opinion, I think money is more well spent with the addition of a strong 3/4 or 1-ton rear at least and a front to match.

    Because C-clips letting go and shattered u-joing and axle shafts really get old after a while!
     
  12. onetonbb74

    onetonbb74 1/2 ton status

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    14 bolts can be built for under a 1000 with a Detroit locker and disc brakes and gears. thats why i have one! my neighbor has 1500 into his 12 bolt (axles, arb, drums/shoes, bearings, gears, outer axle seals, etc), and it still has drums and its broke already once.
     
  13. MaxPF

    MaxPF 1/2 ton status

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    Man, I have got to watch you guys wheel sometime. It should make for some fine entertainment. :haha:

    As soon as I figure out how to diet 300lbs off of the fat bastard, get it to where the pumpkin doesn't dig a trench with anything smaller than 37's, and figure out a way to get some decent 8 lug alloys for less than the cost of Trump's last marriage, then I'm there. :thumb:
     
  14. G-Force8

    G-Force8 1/2 ton status

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    I've never lost a c-clip,snapped a u-joint or broken an axle in a 10 or 12 bolt axle because I've never wheeled hard with 'em!

    I have seen sooooooo many just crumble which is why I wont' mess with them.

    But when I build my Wagoneer and get my Suburban in capable condition I'll have some interesting pics for ya :)
     
  15. Jrgunn5150

    Jrgunn5150 1/2 ton status

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    I dunno what you guy's are drivin, but I have a longbox pickup, and I'm so beyond caring about saving 200 lbs. Basically thats the weight of a buddy, or all the miscellanious crap that in the truck at any given time anyway.

    I'm in the same dillema myself right now, the only issue I'm having is that I don't want to step up to 8 lug wheels too. Thats the only thing holding me back right now, otherwise it would be 14 bolt all the way. And if my 10 bolt does take a poo, I'll get a 14 bolt anyway. I don't see the sense in rebuilding/trying to upgrade something we all know is weak.
     
  16. G-Force8

    G-Force8 1/2 ton status

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    exactly

    and 14-bolts are so inexpensive. I wouldn't pay more than $200 for a standard issue 4.10-geared Full Floating 14-bolt with a Gov-lock. The only acception would be a military CUCV 14-bolt. They have 4.56 gears and a Detroit locker already in them and most of them out there have less than 60k miles on the whole truck that they come off of. For that I'd pay a couple hundred $ more.

    Just curious jrgunn5150 why are 8-lug wheels holding you back? You can score a set of 8-bolt beadlock Hummer rims for $25 each. They're strong,look decent and just under 10 inches wide which will accomodate some fairly wide tires. Heck I just bought (4) of them with (8) 36" Hummer RTII tires with between 80-90% tread for a total of $250.

    Great combo to run while you put money elsewhere and/or save for the wheels and tires you want/need.
     
  17. 87BrnRsd

    87BrnRsd 1/2 ton status

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    What about $550 for a brand new in the crate CUCV 14 ff with 4.56's and a detroit? Thats what I paid for mine. :deal:
    -Harrison
     
  18. G-Force8

    G-Force8 1/2 ton status

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    where did you get a NEW CUCV 14-bolt in a crate?
     
  19. Jrgunn5150

    Jrgunn5150 1/2 ton status

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    I see the crate axles on ebay all the time. The wheels, and the tires. When you add in tires it quickly goes north of 1k, which I just don't have for it at them moment. But by this winter I will, and thats the plan when I do.
     
  20. huntingaddict

    huntingaddict Registered Member

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    another option

    you could also put a 14 bolt SF in. I just put one in my truck, scored it from another member on here. Paid extra to get the 6 lug version. Definitely stronger than a 12 bolt, not as heavy as a FF, plenty strong enough for my 35's and should have no trouble with 37-38's. The lockrights are only like $359, which yes it is more than the one for the FF, but it's still not that bad and I didn't have to change the front or the wheels. I think they are a good option.

    Tom
     

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