GreggymacZ28

When looking for stout rear end options for our cars, im sure anyone who has looked has come to a quick conclusion that there are not many options out there. Also, those few options we do have are expensive. My 10 bolt is still holding together and i am running 1.6x 60 foots, but I have some rpm room at the end of the 1/4 mile and i am doing some more upgrades and would rather take what I've got in the 10 bolt than blow it and be out of luck next season.


One thing that has caught my eye on other boards was the 8.8" swap they did. Now the only way this would be cost effective for me would be if i were able to do the swap for less than or at $900. I have read some build threads over on Ls1tech about guys doing this, and they claim it is easy and just takes some fabrication skills.


If i went this route I would find an 8.8" rear end out of an explorer with a 31 spline and 4.10 gear. Now I have a guy locally that sells these and i could get it around $200. After that i would buy a 10 bolt rear and then cut the axle tubes on the 10 bolt right at the pinion and then cut the axles tubes off of the 8.8" rear 4" from the center of the pinion. There are some more measurements to be had there not saying I've done these I am going off of what others have mentioned. After that I would probably have to have sleeves made to accomodate for the I.D. and O.D. of the axle tubes. Then last i would purchase custom axles to fit for what I am going for. Also for the torque arm mount there is a guy who sells one on ls1tech that looks nice, i am not as worried about this yet as it would be the last step and i am curious if everything else would work first.


Now the questions... First of all, alot of people make this sound easy on ls1tech yet it is rarely mentioned on our board...and another concern of mine is if these rear's are easy to build and sell why isnt there a company mass producing them? Also my concern with doing the 8.8" on my own would be being able to weld the axle in straight without a jig. I have heard of techniques i just dont know if there is a way to insure i am not completely off target. And last alot of people say welding close to the center section(being around 4" away from what a previous person whose done the swap mentioned) can cause alot of issues.

Overall into the 8.8" There would be...


Custom axles - $300
Explorer Rear - $200
10 bolt Rear - $50
Sleeves - $50


Total Cost - $600


That being with initial parts, not including gaskets and other parts needed which im sure would add around another $100-$200. Any body see any flaws in this? I am not headed in this direction yet so i do not have any money invested. I am just looking to see if this route is a considerable one, or if aftermarket rear ends are the clear and only choice.

ZONES89RS

iTrader: (2)

I think that your 600ish plus the 200 or so for random parts is 800ish in from not that far off of a use 12 bolt or 9 inch from moser, strange, ect. I see them go for 1500 or so all day. That is what I got mine for. Then sell your old rear for 300$ and you have 400$ over in a rear that has not only engineering, but more common parts and a torque arm built into the housing. If 400$ if of concern, you would be well pressed trying to make power.

On the other hand, I think it is pretty cool to be able to swap different parts if your skills allow. I just cannot justify it.

DIGGLER

iTrader: (1)

lots of work for little savings. and you will still only have 31 spline axles and a crappy track loc.
a good option would be to buy a used moser/strange 12 bolt with 33 spline axles, correct width, correct housing ends, and better diff for around $1500-1700 setup.

Podium

iTrader: (2)

I would like a 8.8 because it is lighter than a moser 9. I'm sure companies don't make the 8.8 for fbodies because theywould have to sell it cheap enough to entice buyers, but if they sold it cheap enough it would take sales away from the 2k+ 12 bolts and 9s.

GreggymacZ28

This is what I was looking for. My point was trying to see if it really was justifiable to do all that work to save a small amount of money. As for these used 9" and 12 bolts did you guys call the company and ask them if they had a used one? Ive checked racingjunk.com, craigslist and other sites and it is hard to find a used 9" or 12 bolt for our cars with the brackets and everything already installed.

If i could get a used one for 1500 that wouldnt be bad at all. I was thinking before that I would get a quick performance axle housing package for $995 and then just put a spool and 4.10 gear in it. But if i can find a used one that sounds like a better route.

DIGGLER

iTrader: (1)

if you were near sc, i can get you a 12 bolt with 33 spline axles, eaton hd, and aluminum cover for $1700 right now.

ZONES89RS

iTrader: (2)

Just watch the classifieds ect. All over ls1tech and then there are some here as well.

AlkyIROC

9" housing package is around $1000. Includes a direct bolt in housing and axles. You provide the brakes and center section.

If you're spending money to make enough power than you don't feel the 10 bolt isn't going to be good enough then you'll have to spend the money to make sure the entire driveline can handle the power.

The cost and time required to fabricate and install a junkyard diff not designed for a third gen can easily go higher than the cost to buy a proper one. The hardest part about putting some other diff into a third gen is the torque arm.

If you're making enough power to need a stronger diff, you don't want to make a cheap mount to attach the torque arm since it's an essential part of the suspension. If you want to eliminate the torque arm, you'll be completely redesigning the rear suspension which will cost more in time and money than buying a proper diff.

Any kind of diff swap is possible but so many people think it's an easy or inexpensive swap. How hard or cheap it can be depends a lot on your fabrication skills.

I'd double or triple that cost by the time it's finished and ready to drive away safely.

Shagwell

I've done a few 8.8 swaps now, and even with doing the work myself I don't see it being done for under $1k, closer to $1500 by the time it's under the car & functioning better than the stock 10-bolt(suspension geometry corrected, etc). Having done several, personally I only see it as "cost effective" if you have/have access to a unit that already has some upgrades and/or the ability or need to simply swap wheels so that you can suit an existing axle length.

The stock 31-spline track lok becomes a ticking time bomb around 500rwhp. Some take 600-700 for years, some split the first hit at the track with 450-500ish. - Often when they split they hurt the housing. All the custom work you have into the housing, and you could be starting over from scratch if you wound it.

Personally, I wouldn't bother with putting the 10-bolt axles tubes on the 8.8. No point in carrying over drum brakes, and if you can even attempt to fab a tq arm mount for the 8.8 then you can easily fab disc brake mounts as needed. - You already need custom axles, why waste money sticking with c-clip axles that will then require c-clip eliminators(which are problematic) for safety? 9" housing ends and the correspondingly suited axles would make a lot more sense, especially since you're going to need to set it up with an alignment jig either way.


I take a bit different approach on mine than most others seem to. I don't waste the time/effort of trying to bracket up a stock-type torque arm, I simply go ahead & build a custom tubular torque arm to go along with it. Unless you already have a nice aftermarket unit, you're going to want one anyway so why not incorporate it into the swap? Even if you do, it could likely be sold for more than the materials required to build it and you can create a much stronger mounting system to suit the 8.8 better.

chucks_net

I run an 8.8 on my 88 Jeep YJ.

Great rear end. Super strong with a ton of upgrade options.

Not sure why you would weld in new tubes. I think that would kill the conversion for me.

There are hardware kits for Jeeps. Buy the kit with all the brackets you need. measure and mark, then weld in place. I think this would be the same/ similar for a camaro conversion.

For the axles, there are many options but the stock ones should be plenty strong unless you are running 44 inch mudders on your camaro (or 600HP) Then you would drop in chromoly replacements which makes it strong like a big old dana 44 without all the weight.

Reading the post from shagwell.... I completely agree. clips should be eliminated and you want rear disk. Mine was newer so it came with disks and no clips. Makes swapping out axles on the trail easy.

shagwell, that torque arm is badass... great job. I agree the stocker will have to go. Pinion angle should be adjustable and stiffer than stock.

Shagwell

Just for note, with the upgraded parts an 8.8 is stronger than a d44. They have a larger ring gear & pinion shaft, thus better/bigger tooth contact & higher shear strength.

I've been consistent 1.1x 60fts and pushed 200mph on a 12-bolt in the camaro. Physically a 12-bolt & 8.8 are essentially the same.

chucks_net

agreed

I like my 91 Z rear end so far I'm not even sure the exactly what it is or what it is referred to as but it appears to be stock. I need to do more research in this area. Had to open it up to change the pinion seal... the guts looked pretty good for the age and abuse. I see them around pretty often... $600 for one in good shape... no fabbing or screw-ups, just bolt it up. Then just upgrade from there

GreggymacZ28

Shagwell that's a nice setup you made. If you don't mind me asking, what did you do to get the 8.8 up into place with all the correct bracketry? That torque arm is really nice by the way.

Podium

iTrader: (2)

Isnt a 12 bolt a lot heavier than a 8.8?

Shagwell

Podium - I haven't had them on a scale, but physically they are very similar size inside & out so I'd imagine they're within a small % of each other.



GreggymacZ28 - That one & another I've done were on my "table" which is a 2x2 box tubing frame that stands 2' high and is built for holding a complete car on top of. When doing a full build(as that tube chassis/late model suspension street car '68 mustang in the pics) it enables me to set the body @ ride height and build everything to suit. I can cross my arms & lean down to lean against the roof of that one and it still has full suspension travel as if it were stock.

The others have been done with the car & rear on jack stands and simply measuring everything out accordingly. Set it all up at simulated ride height (w/o the springs in place) and work from there.

Johnny Blaze

iTrader: (15)

Swapping it into a leaf spring vehicle is much easier then a 3 link car. There are not conversions kits avalible, there are bolt in 9" and 12 bolts avalible.

brandoz28

iTrader: (1)

I personally wouldn't re-use the axle tubes from the 10 bolt, they're thin and weak, the 8.8 isn't a whole lot better on that front. we get a few of the 8.8's in to get 9" ford ends and almost every one is bent. how bad depends on how the horsepower and weight of the car. That said, since you're doing fab work already, I would go ahead and add a brace to the front like TRZ does.

to make it a good, worthwhile upgrade, I would use strange 8.8 ends, to re-use the explorer brakes, I guess you COULD use 31 splines in it if you want to use that stock posi unit, but as shagwell stated, I don't know how much I would trust it long term!

To do it right, you need an alignment jig, and I would personally build a jig for the mounts for the housing as well. Racecraft sells a mount kit. IMO this is a MUCH MUCH MUCH better way of doing it than using the old mounts from a 10 bolt.


http://www.racecraft.com/index.php?m...roducts_id=706


These are observations/experience from working with housings the past couple years.

the other option would be to save the pennies....and bite the bullet for a 9" setup

GreggymacZ28

Yeah, I went in to work today and my boss took me off to the side and i guess the owner of the company was giving out christmas bonuses this year! So, I have some cash now, and I figure what better to use it on than a 9"! Not sure when Ill get it but since i ran into some extra money I will go that route for sure.

Thanks for all of your guys responses! On Ls1tech everyone seems to act like its an easy build yet you hardly ever see anyone with them which is what led me to my suspicion of it being too good to be true. Oh, I think for the 9" what I am going to do is get the quick performance 9" housing with axles and then get a strange pro racing spool and then richmond or motive 4.10 gear. Hopefully the spool wont be too bad for 1-3 cruises a summer.

mw66nova

iTrader: (13)

i drive a spool on the street...it's a little rough, but not terrible. the worst thing is pulling into a parking spot, lol. but i love having the piece of mind at the track.

have quick performance put an extra side brace on the torque arm mount...ask five7kid why this is so important

brandoz28

iTrader: (1)

They're using solid heims now, i believe they have a side brace kit as well. If you call, talk to Doug.

chucks_net

was whoring in another thread... thought maybe I would ***** my 8.8 in my jeep. Love the axles!

In this pic I just broke my front axle pulling a tree out of the ground (dana 30/ chromoly full shaft converted w/ locker)

Shagwell

Because many that have done it either never put enough power to it to have broken the 10-bolt or they break the tq arm mount because they try to weld soley to the cast center section & don't get enough strength. - lots of people who have never done something will tell you how easy it is judging off the pictures they've seen.........lol

GreggymacZ28

Well, I recently purchased a used moser 9" with 31 spline axles from a member on here(Iroc'nthe87 thanks again Andrew!). The centersection is a stock center section with the case code being C7AW-E 78. I was going to redo the center section with a spool and 4.11 gears but now I am thinking of just keeping the track lok it has in it and swapping the 4.11's in. Anybody know of what I could do to strengthen the track lok and center section a little? I do not plan on running any faster than low 11s so I figured the track lok should be able to handle that. Especially if my 7.5" rear still was,lol.

brandoz28

iTrader: (1)

when you pull it apart, inspect the area around the bearing on the back side of pinion. this area is prone to cracking. I would probably rebuild the track lok, if it hasn't been already. the cap by the gear is the most prone fail point on those, there are billet steel caps available.

those are the big things that I would look for when you pull it apart! also check the axle splines for excessive twist.

glad you were able to find a deal on a used one! putting a rearend under these cars is ridiculously expensive.

AlkyIROC

The C7AWE casting is the most common but will start to fail once you dip into the 9's but heavier vehicles can break them sooner. Here's what the above post is talking about. The support for the pilot bearing can crack and break off. If it breaks off, it will spit the pinion out the side of the diff. I've seen a couple fail like that at the track.

Luckily, I caught mine before it failed. I pulled the pinion to fix a leak and fond the support cracked. A slight tap with a small hammer and it broke right off.







This is what I upgraded to and have never had a problem since plus I can lift it in with one hand.

GreggymacZ28

Thanks guys. I did some research and found a previous post of your's alky saying that the C7AW-E can dip into the 9's and it is actually one of the opinions i read that led me to stick with the track lok. I will definitely check the backside of the bearing for cracks. Really the only reason I am sticking with it is that i know i will not exceed low 11's and my vehicles weight is 3200 with me in it. But if i ever do decide to push it farther i will probably try out a strange s case and a spool. By the way, I would love to pick up the center section with one hand, the stock one is pretty hefty!

GreggymacZ28

Here are some pictures actually. The first one is the entire center section and then the second one shows where the back of the bearing is where yours is cracked alky. Mine appears to be in good condition. Not a crack anywhere along the outside of it.

AlkyIROC

It looks good but is the weak link of a 9". I really abused mine before finding the crack. Go ahead and use it.

brandoz28

iTrader: (1)

looks good, as i said, check the "hat" on the ring gear side for signs of cracking. they will usually break out around the inside of the bolt holes. i've seen them in several pieces upon disassembly.

chucks_net

AlkyIROC... that forged pinion housing is a work of art ...got some drool on my keyboard

AlkyIROC

It's a Moser aluminum bolt through case. Aluminum Daytona pinion support. Aluminum spool.

The ring and pinion, bearings/races/adjusters, bolts and yoke are steel. Everything else is aluminum. I think the whole thing is less than 20 pounds. A similar OEM setup is probably close to 40 pounds if not more.

I also only run 31 spline axles because that's all I need. I could swap out the spool for a steel one to run 33 spline axles but if I wanted to upgrade to 35 spline, I'd buy a new case with the larger bearings instead of using a machined down spool to fit into the small bearing case. A 33 spline aluminum spool for a small bearing case isn't an option but there are some lightweight steel ones available. With the powerglide's 1.76 first gear, I don't multiply torque enough to need large diameter axles even though I put the car on the back pumper twice this year. If I was running a 3 speed transmission then I would need to go right to 35 spline axles.

itsjustabird

iTrader: (1)

I want to say I saw a bolt in moser 9" on racingjunk with suspension complete for 1k if anyones looking better than trying to build a 8.8

GreggymacZ28

I personally have bought a 9" already but that would be a great deal if anyone is interested!

Also, does anyone know what disc brakes will fit the moser 9 inch? Also, what all do you need to purchase? Rotors, calipers, backing plates, brake lines, anything else?

mw66nova

iTrader: (13)

what housing ends do yours have?

GreggymacZ28

Good question, I am not really sure. I don't know what all the housing ends are that moser makes and I am not sure what mine are considering I bought it used. Ill post up a picture maybe you guys would be able to tell me.

GreggymacZ28

Here is a picture... Not sure if it helps.

mw66nova

iTrader: (13)

looks like a gm end to me

GreggymacZ28

Okay cool! That diagram helped alot. That would mean ls1 brakes would fit?

brandoz28

iTrader: (1)

looks like a GM 10/12 to me. should be the same bolt pattern as the LS brakes