Re: Bullet proof GM 12 bolt.
 

It all depends on how much money you want to spend. What you plan on doing with it and what lug pattern you want.
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Re: Bullet proof GM 12 bolt.
 

Wow Mike! That stinks. Were you launching with a trans-brake or off of the footbrake?

Re: Bullet proof GM 12 bolt.
 

Chris that was trans brake launch @3600 RPM with 11 psi in tires.
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Re: Bullet proof GM 12 bolt.
 

Well, at least it was hooking!! Seriously though, I hope you get it put back together quickly so that you can thrash that new combo some more before the end of the year.

Re: Bullet proof GM 12 bolt.
 

whatever happen to this truck? was it ok??

Re: Bullet proof GM 12 bolt.
 

Everything is great. I hade the tubes welded up. Installed moser axles studs for main caps. It's lived far. I have even turned off 2 step and launched at 4600 and the thing lives.

Re: Bullet proof GM 12 bolt.
 

I don't know if mine will be bulletproof or not but here's the setup on my yet to be driven '69 C10 w/12 bolt rear:

Moser #7950 Ford Housing ends (bye bye c-clips)
Moser 30 spline axles
Moser aluminum diff cover
Detroit Truetrac diff
Richmond 3.73's
Welded axle tubes to the center section
1350 Pinion yoke

given my luck, it will probably explode backing out of the driveway on it's maiden voyage...

Re: Bullet proof GM 12 bolt.
 

That sound like my luck.

Re: Bullet proof GM 12 bolt.
 

Because a true Chevy Man will never run afford product like a rear end, transmission, or a motor from a lowly ford the bestt thing they make is electric fans. 12 bolts are superior to 9inches and Dana 60s for the fact that they have less parasitic power lose than the two off brands.

Re: Bullet proof GM 12 bolt.
 

I will let you build me one and we will see how long it takes me to make spaghetti out of it.

Re: Bullet proof GM 12 bolt.
 

Yup,, I gotta agree with Regan 1000%.

I bleed CHevy Orange! But Anything I own that is faster than a 11 second street toy has a bit more beef to it than a 12bolt. But honestly it may be 'based' on the 9",,,, but does not have one single 'ford' part to it.

http://www.small-block-chevy.com/str9in.jpg

So does that make it OK??? LOL

http://www.small-block-chevy.com/ima...istmascane.gif

Re: Bullet proof GM 12 bolt.
 

I wasted time and money beefing up my 12 bolt, once it went into the low 11's it ate parts, now its a Fab 9, like Marv said same applies, not a Ford part in it.

Re: Bullet proof GM 12 bolt.
 

Are the GMC dana 44 rears any good?My 68 has a dana44

Re: Bullet proof GM 12 bolt.
 

Think of this all as an endurance test and a question of what IS the next weakest link.

Here's a set of Strange 31 spline axles that came out of the truck when it was dead hooking and only 580HP

http://www.small-block-chevy.com/ima...10/66axle3.JPG

Re: Bullet proof GM 12 bolt.
 

Dang Marv that is ugly. It almost looks like it could have been a bad forging. Knock on wood but my old heavy a** Dana 60 has probably 1000 passes on it. I've knocked three sets of gears out of it but it still has the same 40 spline Mark Williams axles in it.

Re: Bullet proof GM 12 bolt.
 

If your dead set on GM parts . Take a late model 2500 van Dana 60 semi float and ad ford style ends with wedding ring style bearings and a 35 spline center . Narrow it to fit and weld on perches at the needed pinion angle Should be good to go .

Re: Bullet proof GM 12 bolt.
 

There is no set rule to how fast is "too fast" for a 12 bolt.

71Dragtruck was having problems at low 11s. Mine has made some low 11 sec passes at the track, and is beat on the street like a mouthy hooker at least 3-4 times per week, and as of right now it's holding up.

I'd have to assume that even though my truck is 4500 lbs race weight, my power is applied a lot less violently and I can thank that for a working rear axle.

Stock 12 bolt truck housing, stock 40+ year old axle shafts, auburn LSD, Yukon Gears, and a forged 4340 yoke.

Re: Bullet proof GM 12 bolt.
 

Another important question .... What trans ? Is this a foot brake truck ? Trans brake ? I leave at 4000 of the brake . In a fullsize this would require a substainial rear axle . Footbraking at 2500 would be alot easier on parts

Re: Bullet proof GM 12 bolt.
 

If you're asking me, it's a 4L80E, with a 3600 stall, footbrake on the 2 step to build boost, leaving at about 7 psi.

I agree, there are a lot of variables that affect the longevity of a rear axle, with weight and shock load at the go the two biggest.

Mine is heavy, but leaves soft compared to you guys.

Re: Bullet proof GM 12 bolt.
 

I bought a moser 35 spline bolt in unit. And yes it bolted right up no issues.

I know the 12 bolt guys love to tell you how great they work and it only broke once :) .. But if you add up the cost to build it once and the fix it you could have bought a much stronger rear diff unit.

I have run 12 bolts and have had decent luck broke some others I did not. But I hate doing stuff twice. Lifetime warranty of the wave trac unit rated to handle 1500+ and cost was not to bad I do not recall the price but look it up on the site.


I leave now at 3750 on the cushion ( it will go 4100 on the vert) on the brake and hit the first gun for 100 ( tuning) dead out the hole and the next kit is coming on shortly after :)

Re: Bullet proof GM 12 bolt.
 

I lust after a moser bolt-in 9" setup for my rig.

When my 12 bolt finally bites it, there's no question that's what is going back in it's place.

Re: Bullet proof GM 12 bolt.
 

I can say that I really like the simple set up with mine and knowing that it is overkill for my set up. No big deal if I really build a 1000+ engine. In the event I ever sell it maybe the next guy is the LS twin 72 MM type. No big deal easy to go pretty far with the unit. I have a muscle kit the fab 9 housing is larger in my case I think it would have hit the fuel tank , and I would have had to start over with moving things around.


I love the vid of the 5.3 with a little convertor and some gear mad street truck. Not to say its not moving I am more into the snap your neck when I turn it loose type guy HA HA

Re: Bullet proof GM 12 bolt.
 

anyone running this bolt in 9" setup from Speedway? I'm wondering if 62" is too wide...considering I want to mini tub my truck so I can run my 315/60-15 d/r's or similar/wider and get them up inside the fender. anyway.....would this $425 housing be a tough enough setup w/o going the fab9/etc route? Looks like the axle tubes are already welded? Axle length? it doesn't mention.

http://static.speedwaymotors.com/RS/...L_19d470f8.jpg

http://www.speedwaymotors.com/Bolt-I...cks,80935.html

Re: Bullet proof GM 12 bolt.
 

I hear about Winters quick changes quite a bit....how tough are they?

is this a deal with disc brakes, a spool, and 4.86 gears for $1800 complete?

http://static.speedwaymotors.com/RS/...L_188c6656.jpg

http://www.speedwaymotors.com/Winter...-End,8517.html

Re: Bullet proof GM 12 bolt.
 

A WMS to WMS of 62" is the width of a stock truck 12 bolt from '63 to early '70.