cycleguy04

I plan on getting about 400 HP out of my 350 (hopefully) and my diff already is developing a whine with a mostly stock early 70's Vette engine. It's time for a rebuild or a swap. Should I rebuild the 10 bolt with thicker chromoly axles, ring and pinion, and a posi or swap for a 9"? I drive the car to work every day and get on it when the opportunities present themselves (4-5 times a day). Nothing to crazy though. The most stress I may put on it in the future is getting wide slicks and taking it to the drag strip a couple times a year (maybe).

Also, about the axles, would I have to get a c-clip eliminator kit if I went with non clip axles? I used to have a Jeep and a common swap was a Ford 8.8" with a c-clip eliminator kit.

90camaro355rs

ok first question you had, you could upgrade your 10 bolt with a good set of bearings, then a good ring and pinion set,
Second question, you could go with a set of moser axles and they would do fine,
Third question, if you go with no c clip axles, YES you will need c Clip eliminators, (STRANGE) has a very nice and easy set to install.

Now I have a 72 nova that has had a full roller 355 with around 525 to 550 hp that had a power glide trans with a strange spool, 456 Richmond gears, c clip eliminators in a factory 10 bolt with 29 x 11.5 x 15 drag slicks, I drag raced it for years, never had any problems. That very same car now has a blown 360 with a Muncie 4 speed, same exact rear end, never changed a thing. I am in no way easy when I drive that car.

If the rear end is built right tolerances are correct, you shouldn't have any trouble with the 400 hp you have. imo

big gear head

If you plan on using slicks then don't waste money on the 7.5 10 bolt. It will probably break eventually, if not right away. I don't recommend c clip eliminators for a street car. Some of them are all right, but most are not designed for street use. The axles are probably not going to be the weak part anyway.

cycleguy04

Haha. Exactly what I expect out of forum advice. Two polar opposite opinions. Anybody else? I would like to keep the 10 bolt because it would be much cheaper to modify than buying and modding another axle.

90camaro55rs, what Muncie do you have? I love the whine of the M22. I'm very tempted to get one, but then my wife won't be able to drive it.

big gear head

That '72 Nova doesn't have the same little 7.5 10 bolt that your Camaro has in it. These are 2 completely different rear ends. The '72 Nova 8.5 rear end is a much stronger rear end.

cycleguy04

Ok. Maybe a 9" is the way I should go. My buddy has a 9"out of a truck. He said he could shorten it for me. Bolt third members are not cheap though. If I do go that route could I still retain the torque arm setup or would it be better to do a 4 link?

Marc 85Z28

iTrader: (3)

Given the right setup, the small 10 bolt can and WILL handle more abuse than most give it credit for. And you can do it inexpensively considering that aftermarket axles are a waste of money.

big gear head

Marc, are you saying that you think the 26 spline axles will be fine with 400 HP and slicks? I sure wouldn't trust them.

You can buy torque arm mounts from some of the companies that make after market 9 inch housings. When you narrow the housing you must use a housing fixture to get everything in line with the bearing bore. You can build a 9 inch chunk that will handle 400 HP for about the same money as it would cost to build the 10 bolt, o maybe less.

86_irocz-28

Why not just go with a 4th gen rear end?

Marc 85Z28

iTrader: (3)

I wouldn't trust the 26 spline stuff either, which is why I said "given the right setup".

If you have an automatic transmission a 10 bolt that will live reliably to 500HP+ and low 11 second 1/4s for under $500 is pretty simple. Get a 98+ 4th gen rear with the Zexel-Torsen, keep the gear to a 3.42 or taller and check the setup, solid pinion spacer, and put a LPW cover on it. A 3.73 ratio will still be strong enough, but shorter than that is foolish.

I have the above mentioned axles in each of the cars listed in my sig. The TA has a 3700lb raceweight and has gone a best of 1.48" 60', making around 550 at the crank. It's doing fine 9 years later after 30K+ hard street miles, all on MT drag radials. The Camaro is lighter, and made significantly less power, but has been fine since 2002 - best of 1.65" 60'. With the new setup that should be complete this spring, I will have it in the high 9s on that same 10 bolt at over 600rwhp.

Recommending a 9" for a 400hp automatic car is just downright silly.

big gear head

A 4th gen rear end ('98 to '02) would be much better than the current 26 spline '83 rear end, if you can live with the extra 4 inches. If I had access to a 9 inch and was able to make it fit the 3rd gen without spending much money on it (which he does) I would much rather do that than spend $1500 on parts to build the 3rd gen 26 spline 7.5 (which is what he has). Now that would be down right silly.

Marc 85Z28

iTrader: (3)

I would also like to add that aftermarket axles for the 10 bolt are a complete waste of money for any application. 26 spline should be avoided, period. The stock 28 spline axles are more than adequate. You'll break other parts before the axles.

big gear head

When GM started using 28 spline AAM axles it was a great improvement. As far as 28 spline axles go it would be very hard to beat them. The only reason I would recommend replacing them is if they were damaged in some way.

Orr89RocZ

iTrader: (20)

My personal experience I beat the hell out of my 10 bolt 4th gen rear. Stock takeout 3.42 zexel torsen diff unit. MANY 1.5x 60 foots out of a mid 11 second 383, and a few nitrous passes, 8 passes on spray i think plus alot of street abuse.

Then went to a turbo motor that made closer to 650-700 hp at the time before i chipped a worm gear. That motor went 10.34 at 135.

I feel an automatic stalled car wont hurt them as bad. I would NOT spend money on parts for them tho. Take out 3.42 GM rears from a 4th gen and thats it. More gear you put in them, less teeth material exists and they become weaker. More prone to sheer teeth off.

Now I do have a 3.73 gear in my 10 bolt LS1 car. Many 1.6-1.7 60's and mid low 12 secnd passes. Only a 320 whp car tho but its living at 3600 lbs.

InfernalVortex

iTrader: (4)

Because it's not any stronger than a third gen 10-bolt? They're mechanically the same. Same 7.5 inch ring gear. The only advantage is they got the 28 spline axles, but so did the 89-92 10-bolts.

Their posis will be newer, and the 98-02 Torsen posi is pretty awesome but I dont think it's super well suited to drag racing.

They're better rear axles, but not because they're stronger.

TTOP350

iTrader: (8)

Heck, I wouldn't even say the 4ths are better than the 89-92s, just newer and wider with a different diff choice.
Id also rather have the 89-92 and 93-97 rear disc than the 98-02 stuff

Orr89RocZ

iTrader: (20)

Atleast the 99-02's will have torsen diffs and big disc brakes, a very nice upgrade over clutch style posis. Worm gears dont wear out like clutch auburns and eatons

86_irocz-28

cycleguy04

Thanks for the advice. Once I get my truck running I think I'll park the Camaro in the garage and start tearing into this project. I need to crunch some numbers and see how much a torque armed 9" swap would be vs rebuilding my current 10 bolt. Either way it's going to be mechanical posi and chromoly axles. I like the idea of a 9" because it'll take whatever I throw at it, but I'm guessing it'll be at least twice the cost.

Marc 85Z28

iTrader: (3)

Twice the cost? Not even close. You're looking at $3000-$3500 MINIMUM for the complete unit with the necessary suspension and brake parts.

86_irocz-28

This ^ is why I went 4th gen instead

big gear head

If you do most of the work yourself with the used truck housing you should be able to build the 9 inch for around $1500 to $2000.

cycleguy04

Yeah an empty Moser with axles is 1500! My buddy got a 9" housing that he tried selling me back when I had my Jeep. I'll see how much he wants for it and how much he wants for shortening it.

Marc 85Z28

iTrader: (3)

You need to do quite a bit more than just cutting the tubes to length.

You can find a housing with all mounts (including torque arm) and your choice of axles for just under $1000 from a few different places.

InfernalVortex

iTrader: (4)

You do realize it's not any stronger, right? That all the internal load-bearing parts interchange?

cycleguy04

Yeah, from what I understood, it's just wider.

Marc 85Z28

iTrader: (3)

The case itself and the Torsen differential ARE stronger than their 3rd gen counterparts. 4th gen rear gives you a marginally better case, stronger 28 spline axles, a stronger and more effective differential, a better gear ratio (application dependant), better brake options, and a wider track if you're one of the many that like the 4th gen wheels. And it does all that for around $250. For many mild builds, it's a good choice.

InfernalVortex

iTrader: (4)

Depends on the situation.

1. Torsen is "stronger"? The posis arent what break, they just wear out. The torsen wont wear out, but the auburn posis are not what is breaking the pinion gears. Not all 4th gens got Torsens, only the 98-02 ones, but I agree this is worth the upgrade. I have a Torsen carrier in storage for when I break my 9-bolt.

2. First I've heard of this marginally better case. Sounds likely, but I would imagine it's not all that significant either. Still an improvement if that's the case.

3. I run 17x11 vette wheels. With a 4th gen axle my 17x11's would stick out ridiculously far in the back. I run 1.25" spacers. With a 4th gen rear there's simply no way to run these wheels and it look decent. Just one example that doesn't prove anything except that sometimes the ability to use thinner adapters pays off.

4. The 98-02 brakes require some fabrication to get the e-brake to work. For those of us with no welders and manual transmissions, that gets a little complicated. It's an easily solvable problem with the right tools, though. But my 89 9-bolt has PBR's and 28 spline axles just like every other 89-97 F-body axle. So you dont HAVE to get a 4th gen rear to get decent brakes and 28 spline axles.

Really it just depends on the situation. If you've got some 17x9 SS wheels you want to use and you can find a 98-02 Z axle, you're doing pretty well for yourself by ignoring 3rd gen options.

TTOP350

iTrader: (8)

And the late 89(?) and up 10bolts have the 28 spline axles to.

Orr89RocZ

iTrader: (20)

You have the low offset ones? The popular zr1's in 17x11 usually need 2" spacers as they have a high offset

TTOP350

iTrader: (8)

Not really talking about the ZR1s but
Most cars I've seen that run the 2" spacer, w 4th gen wheels, moves the wheel to the very outside of the wheel lip. (looks a bit weird to me, I like a lil tuck back under the outter lip...

articwhiteZ

iTrader: (56)

The pinon gear is to small in a 7.5 to hold up to anything in the 3.73 /4.11 gears. And 300 plus fpt .and slicks...I.had every thing they sell and made for the 7.5 and could wipe the pinon clean. With the crack of the throttle...it's the first thing thet lets go. You're just fooling yourself thinking that a 7.5 would work for anything other than stock..I've used Richmond. Zoom. And others.

Marc 85Z28

iTrader: (3)

Not only do spider gears break, but so do the differentials. I've seen more than a few Eatons and Auburns crack. I've seen one Torsen do it, but it took a over a dozen low 1.4x 60' passes to break it.

The housing casting is completely different. Bracing is more significant. But like I said, the difference in strength is minor at best.

17x11 do not fit without a minitub, period. Offset, spacers, axle width, quarter panel lip - no matter. They just don't fit. And I don't need anyone arguing with their pics of wheels hanging out trying to argue it. They don't fit on the 4th gen Camaros either. They do, however, fit on the 4th gen Pontiacs.

I loathe my PBR calipers. Only reason I run them is for 15" wheel clearance. Screw piston calipers suck.

I agree. That's the combo I run.

I have over a dozen timeslips with 1.5x 60' and 2 with 1.4x 60' that disprove that. And in a 3700lb car no less. Granted it's with a Motive 3.73 gear set, but gear brand doesn't really matter here.

TTOP350

iTrader: (8)

I used to have a stack of 3.73 and 4.11 gears (different brands) for stock (3rd and 4th) 7.5 housings that busted the pinion teeth off with just street tires in mildly moded cars.
Had one with the pinion broken completely off.
I saw one happen doing a rolling burnout at less than 20mph with street tires.

Some of these 7.5s last a lot longer than they should, very lucky if they do.
Others just let go for no reason. (3rds and 4ths)
I honestly think the pinion housing machining is off on the ones that fail or the housing is flexing.

I also know a guy that was spraying a 400 shot outa the hole on the street with posi 2.73 in a 4th gen.
Claimed he never touched the rear. Found out a few years later he was replacing it once a month with more stock 2.73 4thgen rears because he constantly grenaded them. On the street with slicks.

90camaro355rs

I have the M21 Muncie, if works great its now behind a 360 with chevy with a 6-71 blower and a 10 bolt

90camaro355rs

cycleguy04, my 90 rs has a 550 hp full roller engine with 28 spline axles in it, I have beat it hard, with stock gears, I just put in a mini spool due to it had a one wheel wonder in it, I will beat it up as well.

I am also building a 9 inch to go in my full tube chassis drag car, it is very expensive, the only reason I am going with it, right place right time for all the nec parts.

I say do what you can afford, it seems there are a lot of different opinions about this, some like one some like others, personally its up to you.

Going with a Muncie is ok, I beat it up as well. I bought hardened parts and have had no trouble.

Hope you get it all worked out the way you want it.

articwhiteZ

iTrader: (56)

a dozen...lol ya everybody gets lucky..your not disproven anything. i would get 2 runs out of a set. with 1.3 wheels up hole shot..

when you have one granade! on you top of 3rd gear. you will wish you had a 9".. it took out my U joints. sprag in the tranny.. and coverter. before i could get the car stopped... but what do i know...just your every day low 10 sec street car...with power seats windows and cruse.and im a tad above sea lev..

the last brake was cheap to fix..bolt in 9"by Curri entps. locker 4.11 $2300.SSM ladder bars. as i left the old ones on the 10bolt rear end.$250. coverter B$M warrenty(life costermr/free). new 3.5 alum drive shaft $400...tranny$500.. takes money to go fast more then a dozen times... this was just one fail of the 7.5 rear end..

TTOP350

iTrader: (8)

https://www.facebook.com/LSwonNation...type=1&theater

90camaro355rs

@articwhiteZ, sorry man it sounds like you should have been paying more attention to your car, anyone knows when you drag race whether its a street/drag car or full out race, looking your car over is a must. I would have to say if you had some pro gears, that most likely wouldn't have happened, pay attention I said most likely wouldn't have. besides im so impressed with your 10 sec street car, (sarcasm) The young man said he planed on building a 400 hp engine never did I see it say rwhp, so if its 40 at the crank that's what 320 330 at the rw, I don't see that 7.5 10 bolt built with the right parts and person coming apart unless he neutral drops it every day or dumps the clutch every time it moves.

I really don't see that happening, unless he just wants to beat his car to death.

so now that I have that said let me jump on the 60ft times, mine are 1.32 ta 1.35 60 ft with a 5.88 in the 1/8th mile Pontiac headed 406 with 15.5 ta 1 compression and no I don't use nitrous.

Marc 85Z28

iTrader: (3)

Lucky? Lucky for over a decade on two different heavy cars with over a hundred combined passes and 100K+ hard street miles (all on DRs)? You claimed a 10 bolt with a 3.73/4.11 couldn't handle 300 lb/ft and a sticky tire. You're just flat out wrong. If you're putting up 1.3 short times I agree you have no business running a 10 bolt. AGAIN, the small 10 bolt CAN AND WILL handle 500hp given the right setup.

InfernalVortex

iTrader: (4)

If you put 2.73's in one and have a soft-launching turbo car, sure.

I've seen them break many times at far lower power levels than that, regardless of innards. If you put sticky tires on it, it will go.

There's a fatigue life in these parts. Some last longer than others, but you cant fight physics. These axles were designed for 150hp LG4's to squeeze as much gas mileage out of them as possible.

cycleguy04

Obviously, there are some differing opinions here. As for the 400 HP I want. Don't know if it will be at the crank or at the wheels. All I plan on doing to my LQ4 is a head and roller cam swap, maybe stroke it later down the road.

supr_fly03

iTrader: (2)

Dont listen to all of this internet rhetoric. You will be just fine. I have 400 RWHP and run donut spares on the back and dump the clutch all the time. I have never had a problem haha!

Realistically it is all based on your budget, how far you want to push the limits of the axle, and what you are comfortable driving around at the end of the day. Lots of opinions to sway you on both sides.

Once I do a head and cam swap on my LTI with a tune (shooting for 400+ RWHP), a stronger rear will be next on my list. Until then I hope it holds together and I wont be pushing it with slicks or DR's.

articwhiteZ

iTrader: (56)

when i got my car back from Lingenfelters (1993).they told me the stock rear end was not going to live long. and i worked with it for a year.. and 2 or 3 sets of gears... but i moved on to a stronger rear end.that i know will hold up! ..and looking over my car before a race. is on the check list every weekend..i just dont pull my rear end apart and check to see if my gears are going to let go. when put under force (crystal ball by snap on?)

my 50 state smog car. running 10.30s/10.40s back in the 90's has moved on to be almost a fast car...

heck i might even buy a trailer.. to tow it to the track one day...but im keeping my tilt cruze and power windows!

InfernalVortex

iTrader: (4)

You know how much wider the rear track is than the front with 17x9.5s? 9/16's of an inch per side. The difference between the front and rear track on these cars is about half an inch per side. Basically, If I ran four 17x9.5s with the same offset and the same adapters on all four corners, they would have almost exactly the exact same stance. Any car that uses the same wheel for all four corners and uses 17x9.5s will be externally identical to my car with 17x11's in the rear. I think most people tuck the rear 17x9.5's in a little farther mainly because they can, and I do agree that looks better, but you couldn't even do that with a 4th gen rear.

bowtieboy08

how do i identify this unit? 3.42 zexel torsen diff unit. I know some of the fourth gens have a lesser gear in them...

sofakingdom

iTrader: (1)

Can't see it in the dark. Really stormy out tonight.

If it's a 3.42 Zexel Torsen, then it's a ... 3.42 Zexel Torsen. Not much further "identification" needed, beyond, what model of rear it's for.

4th gens have a range of gears in them, including 3.42. So yeah...

Lots of misinformation / partial truths / outright lies / misconceptions / prejudice / confusion in this thread. Kinda hard to pick out the REALITY from among the noise. I'd recommend, to future users, that they not put too much weight on whatever they read in this thing. (the comments about PBR brakes and "screw piston calipers", which PBRs don't have at all, are pretty typical of the problems)