Bullet proof GM 12 bolt. - Page 2 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Captainfab** · 06-21-2011, 11:57 PM

The TBSS ' have 9.5 SF 14 bolts under them?

I would go with either a Dana 60 or the 9.5 SF 14 bolt, and have it shortened to your needs. The Dana 60's are very common under F250's and the 9.5 SF 14 bolts starting in mid 80's GM C20,K20 and the 2500's from '88 and up.

Quote:

Originally Posted by 68GMCCustom

I too am wondering about rear ends..............truck rears that is.

Can't argue with the toughness of a 9"...also can't put a blue oval part on my GM truck.

Currently have a rebuilt truck 12 bolt with new Eaton posi, 3.73 gears, and "bearing saver" bearings. Running street 275/60-15 BFG's on 8" wheel, but I want to go to a wider 29"-30" tire, preferably MT ET Street drag radials and 4.11 or maybe 4.56 gears. Have a line lock, but its not currently installed. My 6.0L LY6 should be making over 500hp at the crank and is running thru a "built?" 200-4r, and I may add some spray....or preferably a Vortech supercharger later.

That said.......what is the "better GM" choice for a rear end tuff 'enuff to get beat on at the track by a 500+hp motor and sticky tires, yet still be up for street duty for weekends, cruises, long tours, etc. I know I'll also have to do a bit more for my 200-4r (or replace it) for it to live long. As for a rear diff.....I've always thought I'd choose a Dana 60......but the 9.5" 14 bolt semi-floater in our TBSS has me thinking about one of those.

68GMCCustom · 06-22-2011, 12:05 PM

Yes, 9.5" 14 bolt. And its holding up to what guys are throwing at it....taking the stock LS2 to bigger cubes and boosting with forced induction or N2O. The 4L70E "Super Duty" trans has been the weakest link. Our TBSS had nothing but a tune....and is on its 2nd trans so to speak as they rebuilt the original at around 25k mi.? The tunes been out now for a while, and won't go back in until I'm ready to start upgrading parts...which will be within the next 12 mths or so. Its out of warranty this month...and paid off in 12. Then the wife gets something new...and I get the TBSS to add to my "collection of 2"...a '68 and an '06...though I'm working to get my dads old white w/red leather '84 Caddy Fleetwood Brougham to add also. Then I'll have 3 and it will be time to move to a home with more garage/land around it!

***BTW - this also makes TBSS's prime candidates to purchase a salvage truck for the complete LS2/4L70e/9.5" 14bolt drivetrain. Actually, I think the complete chassis is used on the AD series (47-54/55?) trucks/SUVs.

**Captainfab** · 06-23-2011, 12:04 AM

That's interesting. I had no idea that GM put the 9.5" 14 bolt under anything but trucks. I see that they put them under the 6 speed SSR's as well. It's too bad they changed the wheel bolt pattern to 6 x 5", but that would be easy enough to change to 6 x 5.5" if a guy wanted. Do you have any idea on the width of these in the TBSS application?

dgreen · 06-23-2011, 12:09 PM

Quote:

Originally Posted by Captainfab

That's interesting. I had no idea that GM put the 9.5" 14 bolt under anything but trucks. I see that they put them under the 6 speed SSR's as well. It's too bad they changed the wheel bolt pattern to 6 x 5", but that would be easy enough to change to 6 x 5.5" if a guy wanted. Do you have any idea on the width of these in the TBSS application?

you can also try to key word try too find 1990-93 454ss they have 14 bolts in them my old man has a 1990 454ss

djracer · 06-26-2011, 09:58 AM

I personally don't understand why anyone would run anything other than a 9 inch in a street or strip ride.

Marv D · 06-26-2011, 11:05 AM

Kevin.

... and besides,, if someone truly has a 'bullet proof' rear end of any flavor,,, All I can say is you ain't making enough power and don't have enough traction!!! Given enough power you can destroy just about anything. After I twisted 1 Strange axle, then snapped another, Strange themselves sent me to the Dutchman and he forged me a couple out of his special allow. Yup,, here it is.
http://small-block-chevy.com/images/662010/axle2.JPG (big picture)
That's what let go in initial testing of the ol 66 in Feb.

A set of Mark Williams axles in there now. Big tires,,, dead hooking... Somethings gonna give. Again fortifying my point... nothing is 'bulletproof'

KQQL IT · 06-26-2011, 02:38 PM

Marv Thats a sweet pic...

Marv D · 06-26-2011, 05:47 PM

proof that my dad was right. Given enough time I could break an anvil .

Yeah that pic is a cool example of the grain structure of a forged alloy ain't it!

KQQL IT · 06-26-2011, 06:33 PM

Pops used to run 40spline summer bros in his off road racer and would replace them after a full turn...
Posted via Mobile Device

Blue Rat · 06-27-2011, 08:20 PM

Thanks guys for the posts. I did not mean literally bullet proof. Just want something that I do not have too go through in six months after building it.

bigjimzlll · 07-03-2011, 02:49 AM

Quote:

Originally Posted by KQQL IT

Pops used to run 40spline summer bros in his off road racer and would replace them after a full turn...
Posted via Mobile Device

I run an old set of Top Fuel Summer Bros axels in my junk. They are only 26 spline but are the same diameter of a 40 spline.
I was going to swap them out, but they are still str8 and un-twisted

KQQL IT · 07-03-2011, 03:03 PM

Pops old class 4 racecar. Built in 76, still racing today.

Rannos · 07-22-2011, 09:33 PM

I would beef up the 12 bolt truck rearend. My brothers 65 went a best of 8.90's on a 12 bolt with 468 with a trans break. Here is a link of the video the night the trans break started to fail.... you'll notice as he staged the truck starts creeping.

‪65 chevy truck‬&rlm; -...

fastwillie 696969 · 07-22-2011, 09:41 PM

1/8 mile ?

Rannos · 07-22-2011, 09:51 PM

That pass is 1/8th yes... he ran high 5.70 to 6.0's in the 1/8th.

fastwillie 696969 · 07-23-2011, 12:12 AM

if you build it they will come

68 C-10 KID · 07-30-2011, 07:22 PM

If ya plan on running big slicks and big power take the advise from the other members and weld the tubes up to the center section.
This happened to me last night from not having the tubes welded.

KQQL IT · 07-30-2011, 08:14 PM

Thats ugliness.

djracer · 07-31-2011, 01:22 AM

I hate to see that happen to you. How much stuff did it tear up?

68GMCCustom · 07-31-2011, 03:52 PM

ouch

fastwillie 696969 · 07-31-2011, 06:28 PM

what pinion angle is that set at ?

BigDan3131 · 07-31-2011, 11:52 PM

If money were no object I would be all over a Halibrand Quick Change in a heartbeat but because money is unfortunately an issue I would buy a Strange S-60 rearend.

68 C-10 KID · 08-01-2011, 11:19 PM

Kevin,
So far all I can tell is it banged up my cross member destroyed the drive shaft, and spun the center section. I should know by next weekend what the in side looks like. I spun the yoke by hand and every thing looks good. I have a steel 1350 yoke on the pinion and it won the battle. I can't believe the mufflers didn't get beat up.

Fastwillie,
I'm not sure what it spun to. I can crawl under it tomorrow with a angle finder. The drive shaft was about 3*

I like the way you think BigDan. For now I'm just going to send this good used 12 bolt to the dutch man and have them weld it up.

68 C-10 KID · 08-01-2011, 11:22 PM

Ready for the Dutchman

Captmike · 08-02-2011, 09:21 AM

I'm trying to get some ideas for my 68.
It has the original six lug peg leg and I want to convert it to posi.
Alot of product choices out there and would like some help narrowing it down.
I have a M-22 4 spd in it behind a SBC with + or - 500 hp.
Thanks!

06-22-2011, 12:05 PM	#27
68GMCCustom Truck and auto performance nut Join Date: Feb 2007 Location: McKinney,Texas Posts: 3,848	Re: Bullet proof GM 12 bolt. Yes, 9.5" 14 bolt. And its holding up to what guys are throwing at it....taking the stock LS2 to bigger cubes and boosting with forced induction or N2O. The 4L70E "Super Duty" trans has been the weakest link. Our TBSS had nothing but a tune....and is on its 2nd trans so to speak as they rebuilt the original at around 25k mi.? The tunes been out now for a while, and won't go back in until I'm ready to start upgrading parts...which will be within the next 12 mths or so. Its out of warranty this month...and paid off in 12. Then the wife gets something new...and I get the TBSS to add to my "collection of 2"...a '68 and an '06...though I'm working to get my dads old white w/red leather '84 Caddy Fleetwood Brougham to add also. Then I'll have 3 and it will be time to move to a home with more garage/land around it! **BTW - this also makes TBSS's prime candidates to purchase a salvage truck for the complete LS2/4L70e/9.5" 14bolt drivetrain. Actually, I think the complete chassis is used on the AD series (47-54/55?) trucks/SUVs. __________________ Kurt - '68 GMC short step - NIB '09 LY6 6.0L crate motor w/mods, NIB '12 crate 4L85e w/billet 3k stall Circle D, 3.73 posi 12 bolt, DynaTech f-swap headers, 3/4 drop, handling mods, etc. - my toy '72 Chevy LWB C-10 Highlander - 350/350 ps/pb/tilt/ac - not original but close '06 Chevy TrailBlazerSS - LS2/4L70e - little black hot rod SUV - my DD '18 Kia Sorento - wife's econo-driver '95 Chevy S10 - reg cab shortbed, LS, 4.3, auto... my '68's powertrain and chassis build -links broken A surprise phase - carb to efi -links broken Last edited by 68GMCCustom; 06-22-2011 at 12:14 PM.*

06-23-2011, 12:04 AM	#28
Captainfab 60-66 Nut Join Date: Mar 2007 Location: Coeur d'Alene, Idaho Posts: 23,246	Re: Bullet proof GM 12 bolt. That's interesting. I had no idea that GM put the 9.5" 14 bolt under anything but trucks. I see that they put them under the 6 speed SSR's as well. It's too bad they changed the wheel bolt pattern to 6 x 5", but that would be easy enough to change to 6 x 5.5" if a guy wanted. Do you have any idea on the width of these in the TBSS application? __________________ Power Steering Box Adapter Plates For Sale HERE Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE Hydroboost Mounting Plates HERE

06-26-2011, 09:58 AM	#30
djracer Registered User Join Date: Feb 2001 Location: Wetumpka, Al, U.S. Posts: 8,891	Re: Bullet proof GM 12 bolt. I personally don't understand why anyone would run anything other than a 9 inch in a street or strip ride. __________________ Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole!

06-26-2011, 11:05 AM	#31
Marv D Registered Truck Offender Join Date: May 2008 Location: hells training ground (aka Ariz) Posts: 3,118	Re: Bullet proof GM 12 bolt. Kevin. ... and besides,, if someone truly has a 'bullet proof' rear end of any flavor,,, All I can say is you ain't making enough power and don't have enough traction!!! Given enough power you can destroy just about anything. After I twisted 1 Strange axle, then snapped another, Strange themselves sent me to the Dutchman and he forged me a couple out of his special allow. Yup,, here it is. http://small-block-chevy.com/images/662010/axle2.JPG (big picture) That's what let go in initial testing of the ol 66 in Feb. A set of Mark Williams axles in there now. Big tires,,, dead hooking... Somethings gonna give. Again fortifying my point... nothing is 'bulletproof' __________________ Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral.

06-26-2011, 02:38 PM	#32
KQQL IT At the body shop. Join Date: Aug 2009 Location: Land of fruits and nuts. Posts: 5,127	Re: Bullet proof GM 12 bolt. Marv Thats a sweet pic... __________________ " That didnt make it any newer " " Dont antique the equipment "

06-26-2011, 05:47 PM	#33
Marv D Registered Truck Offender Join Date: May 2008 Location: hells training ground (aka Ariz) Posts: 3,118	Re: Bullet proof GM 12 bolt. proof that my dad was right. Given enough time I could break an anvil . Yeah that pic is a cool example of the grain structure of a forged alloy ain't it! __________________ Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral. Last edited by Marv D; 06-26-2011 at 05:48 PM.

06-26-2011, 06:33 PM	#34
KQQL IT At the body shop. Join Date: Aug 2009 Location: Land of fruits and nuts. Posts: 5,127	Re: Bullet proof GM 12 bolt. Pops used to run 40spline summer bros in his off road racer and would replace them after a full turn... Posted via Mobile Device __________________ " That didnt make it any newer " " Dont antique the equipment "

06-27-2011, 08:20 PM	#35
Blue Rat Registered User Join Date: Dec 2010 Location: Arkansas Posts: 608	Re: Bullet proof GM 12 bolt. Thanks guys for the posts. I did not mean literally bullet proof. Just want something that I do not have too go through in six months after building it.

07-03-2011, 03:03 PM	#37
KQQL IT At the body shop. Join Date: Aug 2009 Location: Land of fruits and nuts. Posts: 5,127	Re: Bullet proof GM 12 bolt. Pops old class 4 racecar. Built in 76, still racing today. __________________ " That didnt make it any newer " " Dont antique the equipment "

07-22-2011, 09:41 PM	#39
fastwillie 696969 ~Rest In Peace~ Join Date: May 2005 Location: CALIFORNIA NOR CAL Posts: 9,707	Re: Bullet proof GM 12 bolt. 1/8 mile ? __________________ is it fast ? it has a lighting bolt donut? B___H please, I can remove 90% of your so called "beauty" with a kleenex

07-22-2011, 09:51 PM	#40
Rannos Registered User Join Date: Feb 2010 Location: New Caney, Texas Posts: 356	Re: Bullet proof GM 12 bolt. That pass is 1/8th yes... he ran high 5.70 to 6.0's in the 1/8th.

07-23-2011, 12:12 AM	#41
fastwillie 696969 ~Rest In Peace~ Join Date: May 2005 Location: CALIFORNIA NOR CAL Posts: 9,707	Re: Bullet proof GM 12 bolt. if you build it they will come Attached Images __________________ is it fast ? it has a lighting bolt donut? B___H please, I can remove 90% of your so called "beauty" with a kleenex Last edited by fastwillie 696969; 07-23-2011 at 12:20 AM.

07-30-2011, 07:22 PM	#42
68 C-10 KID Mean Green Join Date: Sep 2007 Location: Portland, OR Posts: 522	Re: Bullet proof GM 12 bolt. If ya plan on running big slicks and big power take the advise from the other members and weld the tubes up to the center section. This happened to me last night from not having the tubes welded. Attached Images __________________ 427 SBC 683HP & 590ftlbsTRQ @ fly wheel. 60'-1.38 1/4-10.43 MPH-124.6 New ET current 4/2019 AKA MEAN GREEN.

07-30-2011, 08:14 PM	#43
KQQL IT At the body shop. Join Date: Aug 2009 Location: Land of fruits and nuts. Posts: 5,127	Re: Bullet proof GM 12 bolt. Thats ugliness. __________________ " That didnt make it any newer " " Dont antique the equipment "

07-31-2011, 01:22 AM	#44
djracer Registered User Join Date: Feb 2001 Location: Wetumpka, Al, U.S. Posts: 8,891	Re: Bullet proof GM 12 bolt. I hate to see that happen to you. How much stuff did it tear up? __________________ Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole!



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07-31-2011, 03:52 PM	#45
68GMCCustom Truck and auto performance nut Join Date: Feb 2007 Location: McKinney,Texas Posts: 3,848	Re: Bullet proof GM 12 bolt. ouch __________________ Kurt - '68 GMC short step - NIB '09 LY6 6.0L crate motor w/mods, NIB '12 crate 4L85e w/billet 3k stall Circle D, 3.73 posi 12 bolt, DynaTech f-swap headers, 3/4 drop, handling mods, etc. - my toy '72 Chevy LWB C-10 Highlander - 350/350 ps/pb/tilt/ac - not original but close '06 Chevy TrailBlazerSS - LS2/4L70e - little black hot rod SUV - my DD '18 Kia Sorento - wife's econo-driver '95 Chevy S10 - reg cab shortbed, LS, 4.3, auto... my '68's powertrain and chassis build -links broken A surprise phase - carb to efi -links broken

07-31-2011, 06:28 PM	#46
fastwillie 696969 ~Rest In Peace~ Join Date: May 2005 Location: CALIFORNIA NOR CAL Posts: 9,707	Re: Bullet proof GM 12 bolt. what pinion angle is that set at ? __________________ is it fast ? it has a lighting bolt donut? B___H please, I can remove 90% of your so called "beauty" with a kleenex

07-31-2011, 11:52 PM	#47
BigDan3131 Registered User Join Date: Jun 2006 Location: Maple Valley, WA Posts: 1,913	Re: Bullet proof GM 12 bolt. If money were no object I would be all over a Halibrand Quick Change in a heartbeat but because money is unfortunately an issue I would buy a Strange S-60 rearend.

08-01-2011, 11:19 PM	#48
68 C-10 KID Mean Green Join Date: Sep 2007 Location: Portland, OR Posts: 522	Re: Bullet proof GM 12 bolt. Kevin, So far all I can tell is it banged up my cross member destroyed the drive shaft, and spun the center section. I should know by next weekend what the in side looks like. I spun the yoke by hand and every thing looks good. I have a steel 1350 yoke on the pinion and it won the battle. I can't believe the mufflers didn't get beat up. Fastwillie, I'm not sure what it spun to. I can crawl under it tomorrow with a angle finder. The drive shaft was about 3* I like the way you think BigDan. For now I'm just going to send this good used 12 bolt to the dutch man and have them weld it up. Attached Images __________________ 427 SBC 683HP & 590ftlbsTRQ @ fly wheel. 60'-1.38 1/4-10.43 MPH-124.6 New ET current 4/2019 AKA MEAN GREEN.

08-01-2011, 11:22 PM	#49
68 C-10 KID Mean Green Join Date: Sep 2007 Location: Portland, OR Posts: 522	Re: Bullet proof GM 12 bolt. Ready for the Dutchman Attached Images __________________ 427 SBC 683HP & 590ftlbsTRQ @ fly wheel. 60'-1.38 1/4-10.43 MPH-124.6 New ET current 4/2019 AKA MEAN GREEN.

08-02-2011, 09:21 AM	#50
Captmike Registered User Join Date: Aug 2011 Location: Diamondhead, Ms. Posts: 12	Re: Bullet proof GM 12 bolt. I'm trying to get some ideas for my 68. It has the original six lug peg leg and I want to convert it to posi. Alot of product choices out there and would like some help narrowing it down. I have a M-22 4 spd in it behind a SBC with + or - 500 hp. Thanks!

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