Let's say you needed something more than a 12-bolt...

[Dogmeat]

I've seen a lot of guys with the pro street and pro comp cars that run Dana 60 truck axles for the rear ... at least I think that's what classes I saw? Could be mistaken, but either way ...

Do you guys know of anyone who does f-body conversions on late-model GM 14 bolts?

I can't immagine that a 14 bolt would be more expensive than a Dana 60, considering how abundant they have been in the last 20 years, and even used D60's are going for $2500 these days. I figure even if you had a 9.5" 14 bolt with drum brakes, you could have that for under $1000 and then just pay somone to re-weld the spring perches so it'd fit an f-body wouldn't you?

Anyone got any ideas?

[CT Morgan]

No idea, but how do you figure you need "more than a 12 bolt"? :dunno: A built 12 will handle just about all you need. ;)

[Dogmeat]

I'd think if you were pushing 600 rwhp, and really liked to drive your car, it wouldn't be too terribly hard to go through 12 bolts pretty quickly :)

I mean really, a 12 bolt isn't a whole heck of a lot stronger than the 8.5" 10 bolt. ...

[jmd]

Well, the 8.5" is a good rear but none are easily swappable into 82-up F's, so it's wise to bypass it and go for the 12 bolt when going custom.

A friend ran a N/A 4spd car that ran 10.70's with a Dana 60.

2500$ for a used truck D60? Seems kinda :eek: since an off-road magazine (can't remember which one; Feb issue?) picked up an 86 Army pickup w/ D60/14bolt diffs for 2500$ at auction.

Gonna make more power than a 9 second at sea level 3500lb car w/ a 8000rpm Rat? Try a D60 and go from there. JMO. :)

[Blown 98 Z]

A Moser 9 inch with a Locker or Spool is all you need.

Don

[CT Morgan]

Originally posted by Dogmeat
I'd think if you were pushing 600 rwhp, and really liked to drive your car, it wouldn't be too terribly hard to go through 12 bolts pretty quickly :)

I mean really, a 12 bolt isn't a whole heck of a lot stronger than the 8.5" 10 bolt. ...

AH... you're talking about stock GM 12 bolts? Sorry... different animal completely. No one I know is converting stock 12's into LS1 f-bodies though. Both Strange and Moser use custom housings which have larger axle tubes and then stuff the rears with racing components.

600 rwhp isn't a problem at all for the aftermarket 12's, but it can be a little stressful on the Eaton HD posi they use if you are launching at high rpms on slicks. I had to swap to a full spool on mine to handle 700 in a 3,750lb car on full slicks. To be expected though. ;)

Either way you're faced with a locker of some kind or a spool for serious power applications on the track.

[INDA10Z]

ive seen low 8's on a 12 bolt so if you have somethin faster than that I need to see it--600rwp isnt going to over limmit a 12 bolt
use GM gears --do not use strange or richmonds and have them set up by someone who does it the way they need to be done and not to- get it out the door;)

[PC PaiN]

Doesn't CT Morg have 600RWHP+ and a 12 bolt ;)

[Goober]

Originally posted by Dogmeat
I'd think if you were pushing 600 rwhp, and really liked to drive your car, it wouldn't be too terribly hard to go through 12 bolts pretty quickly :)

I mean really, a 12 bolt isn't a whole heck of a lot stronger than the 8.5" 10 bolt. ...

:haha:
I know a couple of guys with 8.8 rear ands and 12 bolts and they drive there cars to work and put down 600+ rwhp and 600 + tq on the spray. I dont think you will go though the rear end unless you throw more than 2000hp at it. The are pretty tuff rear ends. If you have that kinda power you are no longer even street driving the car.

[Dogmeat]

Originally posted by CT Morgan
AH... you're talking about stock GM 12 bolts? Sorry... different animal completely. No one I know is converting stock 12's into LS1 f-bodies though. Both Strange and Moser use custom housings which have larger axle tubes and then stuff the rears with racing components.

Oh wow, yeah that is a totally different story, I had no idea that Moser and Strange were using their own housings, I thought there were just "overbuilding" what was a stock unit .... Yeah, I had no idea they were basically a "one-off" 12 bolt or something like that.....

I dunno, I guess I just figured that if guys who are running stock motors but 37" tires on their pickups can bust up a stock 12 bolt pretty easily, a car that's pushing 600 horsepower would be able to also ... heh :D

[CT Morgan]

Originally posted by Dogmeat
Oh wow, yeah that is a totally different story, I had no idea that Moser and Strange were using their own housings, I thought there were just "overbuilding" what was a stock unit .... Yeah, I had no idea they were basically a "one-off" 12 bolt or something like that.....

I dunno, I guess I just figured that if guys who are running stock motors but 37" tires on their pickups can bust up a stock 12 bolt pretty easily, a car that's pushing 600 horsepower would be able to also ... heh :D

Yep different animals completely although with the correct internals even on a stock axle tubed 12 it would be no comparison to a stock GM 12 bolt.... at all. And the stresses of a truck can be just a little different. ;)

Like I said, my Eaton HD couldn't keep up to the task even though Moser claimed it would hold 800+ hp. No granted it only has a clutch grabbing and isn't grenaded, but it did that shit just during a tuning session. ;)

BlackWS602: Jon... shhh!!! :p That "+" is always a mystery. :) LOL... although I did mention 700 earlier.

[wannafbody]

the Dana 60 in a fbody has been done- Stropes put one in a Purple WS6 with a 382 stroker and twin turbos-definitely a big buck job

[thechef]

if you are worried about breaking a aftermarket 12 bolt go with a aftermarket 9inch and a spool and it will be more than you need
we have several customers in the 600rwhp area and only one has had a problem witht he posi now he has a spool

our shop car has a 9 in and has never had a problem and we run 8s@150+mph with the 98 camaro and a bit os NOS:p

[Dogmeat]

ok, I'm not familiar with the term "spool" ....

How is that different from a posi or a locker?

[jmd]

A spool is locked all the time. It is not a "differential" in the sense of being able to differentiate rotation of the axles separately. The axles rotate together, 1:1 to each other, period.

Something we should keep in mind in this thread is that trucks can be harder on rears off-road than an equivalent hp / tq car can be on them on-road. The loading & unloading of the gearset and parts is pretty hefty in a 4x4 in the conditions some are used in.

So the qualifying "an 8 second car would be cool with ....." isn't necessarily the full answer here.

[MeentSS02]

From the research I've done, it sounds like I'm gonna want a locker, but I take it there are no locker options available for a 12 bolt? I only seem to find them available with a 9 inch for some reason...

[Dogmeat]

So ultimatley a spool is the same thing as a locker then?

It just locks your spider gears together basically?

[MeentSS02]

Originally posted by Dogmeat
So ultimatley a spool is the same thing as a locker then?

It just locks your spider gears together basically?

Nope...a spool is always locked. A locker is the middle ground between a spool and a posi unit...it kinda works like a ratchet. When you are going straight, it acts like a spool, and has a good deal more resistance to unlocking than a posi unit would, but it WILL unlock and allow the outside wheel to spin faster than the inside on sharp turns. Make sense?

[Dogmeat]

I was always under the impression that a Limited Slip would allow slight variances in axle shaft speed, but a locker effectivley locked your spider gears together and hence your axle shaft speeds on both sides of the diff were always constant?

I don't see how a locker allows for any variance in the axle shaft speeds....:confused:

[jmd]

Originally posted by Dogmeat
I was always under the impression that a Limited Slip would allow slight variances in axle shaft speed, but a locker effectivley locked your spider gears together and hence your axle shaft speeds on both sides of the diff were always constant?

I don't see how a locker allows for any variance in the axle shaft speeds....:confused:

A detroit locker has a mechanism that unlocks with a sideload. Picture the inner wheel on a left hand turn. The axle being pulled outwards will unlock the mechanism and allow the differential to act as an open carrier. With low or no lateral load (driving straight ahead,) the mechanism locks once again.

I am not 100% on the inner wheel pull item. It might be the outer wheel pushing in that unlocks it. But you get the idea.

[MeentSS02]

Originally posted by jmd
A detroit locker has a mechanism that unlocks with a sideload. Picture the inner wheel on a left hand turn. The axle being pulled outwards will unlock the mechanism and allow the differential to act as an open carrier. With low or no lateral load (driving straight ahead,) the mechanism locks once again.

I am not 100% on the inner wheel pull item. It might be the outer wheel pushing in that unlocks it. But you get the idea.

That sounds right to me...I saw one on a TV show once upon a time, and it worked just like that (he demonstrated it). The dude had to pull on it to get it to unlock, then he could spin that one side freely. To me, it would be the best way to go if you plan on beating on your car...yeah, you'll prolly get a little more tire wear since it won't unlock every single time you go around a corner (like on a long turn on an interstate), but it'll still give you more flexibility than a straight spool, and more durability than a posi-type unit.