89T-top

how hard would it be to make an 8.8in fox mustang rear fit on a 3rd gen camaro?

Apeiron

Hard

89T-top

Im asking becuase I have one with a set of 3.55 gears.

JTNKTZ

iTrader: (10)

Ford in GM? Nah....

AlkyIROC

Completely change the rear suspension or find some way to attach the torque arm onto the 8.8. I'm not even sure what the length difference is between the 2 diffs.

It's usually cheaper in the long run and easier to just buy an aftermarket bolt in 12 bolt, 9" or Dana 60 for a third gen.

89T-top

Thanks for the info. was just curious to see if anyone had done this.

AlkyIROC

There have been people who have done it but it's not an easy or direct swap into a third gen. If you have lots of time and fabrication skills, anything can be made to fit.

iroc a 86 berli

a ford 9in is the most popular swap. they make direct bolt ins.

customblackbird

iTrader: (15)

i wanted to so the same thing, swap a ford 8.8 in my formula 350. they are easy and cheap to build, they can also handle GOBS of HP. ive heard and read that they can be built to handle more than a 12bolt.

the only prob that i see is that its a upper/lower LCA rear and the third gen is a 3 link, LCA, panhard rod, and tq arm. all u would have to do is weld up a bracket/ brace for the top 2 LCA's. and relocated the angle of the lower control arms on the rear. prob is that the rears axle shafts are supposidly pretty thin and not thick like the 9bolt/ aftermarket rears so welding will be tuffer.

im not sure on the length of the rear so tire fitment could be difficult. im still thinking i might do it. too bad i already installed my jegster tunnel mount tq arm :/

Apeiron

If it was that easy...

gregsz-28

iTrader: (1)

If he already has the 8.8, why not? If the axle shaft's are the same diameter as that of a third gen rear, you could probably just cut the brackets off your current axle to use. The hardest part is the torque arm mount, which someone could take pics of their custom set up to show you, for ideas. If you don't have the ability to weld something, from lack of equipment or experience, I've found that there is usually someone that'll do it for free, and if not free, cheap.
This project could probably be done over a weekend.
Don't forget brake lines though, and you might need wheels with different backspacing, too.

Apeiron

It's not terribly easy to securely weld a torque arm mount to a cast iron differential housing.

iroc a 86 berli

just save your time and go with a 9in, you will end up wishing you had in the long run. put it in and forget it. or build your own, there are many companays that make bolt ins, try and mock theres up.

gregsz-28

iTrader: (1)

Yeah, it would be easier to go with a 9". You could get a used Ford one for a couple hundred $, and then you don't have to worry about welding to iron, because you can make a torque arm mount that is mostly bolt-on, and you don't have to weld to any iron.

But easier isn't necessarily cheaper.

AlkyIROC

Buy the 9" housing package from places like Moser. It comes with the housing and axles. Get them with 31 splines. The third gen bolt in package should use the third gen brakes. Pick up a center section locally or from a junk yard that has a 31 spline carrier (posi, open etc) with whatever gear ratio you need and pop it in. The housing package is around $1000 plus the cost of the center section you find locally. You could install a proper 9" for less than $1500.

www.spohn.net has the housing package for third gen members.

You could try and find a junkyard 9" housing and adapt the available 9" torque arm bracket onto it but then you have other issues to deal with. First of all, you'll need to find a diff the proper width or very close to it. Modern truck diffs are all too wide unless you find one at least from the early 70's. If the diff wasn't out of a car then it will have the large Ford bolt pattern and you won't find a good car rim that will fit. At least the car diff will have the small bolt pattern and you can pick up rims with the ford 5 on 4-1/2 bolt pattern. Even then, what you save on the diff, you'll spend extra buying new rims and redoing the brake plumbing and park brake assembly because you'll be using the Ford brakes. All the other mounts for the diff can easily be cut off the third gen diff and welded onto a 9" diff.

In the long run, it's still easier and cheaper to just accept the cost to buy a complete bolt in package.

customblackbird

iTrader: (15)

arent the ford 9" housings for our cars the same if not more expensive then the 12bolts.... strange/moser wants like 2400 or something for a complete setup for our cars.... thats insane. i thought i priced the 9" at the same/more. the 9" would be stronger yes but the ford 8.8 is stronger than the 12bolt from what i hear.

prob is... is that in northern NJ there isnt many junkyards around. id say if u already have the ford 8.8 be unique and try to get it to work. the ford brakes suck big time tho even on the 9". thats the only draw back. u could cut off the axel ends and weld on aftermarket peices for like baer or something.... since u saved the money on the housing.

the upper LCA mounts u would have to make would be easy.... get a peice of 1" or 1.5" tubing prob .095" thick and just weld aross from the subframes and mount brackets for the upper LCA. ive seen how its on stock mustangs and its basiacally thin *** sheet metal make brackets spot welded to the floor pan. its cr@p.

MillerTime21

I put a 8.8" in my 96 blazer. Around here you can pick up an 8.8" with a 4.10, 31 splined, posi, disc brakes for under $200. Your not going to find a 9" or 12bolt for that price.

Apeiron

Where are you going to find room to put upper LCAs and mounts without cutting up the back half of the car?

iroc a 86 berli

wouldnt it be easier to relocate the brackets on the housing instaed of hacking up a third gen to install a mustangs quad shock crap or whatever it is.

the bakes are your factory 3rd gen disc or drum brakes. they bolt to the moser/aftermarket housings. or if your fabing it, why not get the stock caliper brakets and weld them on.

customblackbird

iTrader: (15)

the upper control arms for the rear are tiny. they are less than 6" long. i kno bc my friend races and owns 3 fox bodies. theres more room than from the rear to the body.

yes u could relocate the housings brackets.... thats what i would do with the rear LCAs to fit the stock 3rd gen, just hack off the original LCA mounts and weld them to the ford 8.8, then i would jut fab something to the firebird that allows the use of the upper control arms. and how are u gona call a ford 8.8 rear crap? those cars dip into the 12s easily without touching the rears. the ford 8.8 is stronger than our 10bolt/9bolts could ever be... and can be built stronger than the 12 bolt.

and im sure u could weld on aftermarket axel tube ends for the stock brakes if u wanted.... thats no biggie and prob what i would do.

all in all u could just get a bolt in 12 bolt or 9".... or u could be unique and fab up something to get the 8.8 to work... theres a ton of parts for the 8.8 and they are super cheap compared to the 12bolt/9". me i would prob do the 8.8 just to be different.

jamon8

iTrader: (3)

I am pretty close to doing that to a 12bolt out of a diesel truck

I dont need any more gear than a 2.77

you just have to be concerned with the lenth of the axles

I dont want to have to cut axle tubes and buying new custom lenth axles.

iroc a 86 berli

custombbird, by all means i know the 8.8 is stronger then are stock sh*t, (quad (4) shocks is on the older fox bodys and it is crap, it limits tire size much worse then are cars) i to have a buddy with a merc capri and i know his rear will outlastmine..that sounds bad lol, i was under the impression that you where saying to integrate a mustangs rear suspension as well as the rear end. anyways doesnt matter, just flappin my gums.

customblackbird

iTrader: (15)

lol its ok iroc a 86 berli.... i wasnt heated. yea i kno about the shocks on the fox bodies. some guy actually just found out that a QA1 rear adjustable shock from the mustang fits the third gen.... and is about 1/2 the price!!

i would def take off all the sustpenion mounting from the 3rd gen rear and transfer it over to the 8.8, like LCA and shock mounts and brakes, then fab the upper control arms to the third gen.

if u can weld the swap is gona cost very little compared to buying a drop in housing and the ford 8.8's can be had for nothing almost. just an idea, get it to work and u'll have alot of ppl interested in how u did it

89T-top

I can't weld, but my father in law did it for a living and lives right next door.

Oh well just an Idea for now. The 8.8 (with 3.55 gears) rear is on my 87 mustang gt. the body is junk, rusted floor boards rotted out strut towers so my buddy is taking the motor and trans (he gave me the camaro) and put it in a better body, but the rest of the car is mine.
So I will take the rear end off of the stang and put it in my father in laws barn for now.

It would make a kick *** rear end if I ever wanted to make some real POWER.
Just the only thing is my stock GM 7.5 has a 2.73 gear wile the 8.8 is bigger stronger and has 3.55 gears.

I'll have to go measure the 8.8 and then the 7.5 and see what the difference is. they both have 15x7 wheels on them.

customblackbird

iTrader: (15)

i think the axel tubes are different size but im not sure. the most important is the axel length. u will need diff size wheels with a diff size offset/backspacing. also i would def change over to the 5lug axels. that 4 lug is CR@P.

if ur lucky the axel tubes will be the same size and your axel lengths will be close. hopefully in the range of the 4th gen rear whish is wider by 2" vs our stock so its still not a direct bolt in.... since the tires will stick out.

89T-top

here is somthing I found.

http://www.theturboforums.com/smf/in...topic=104354.0

basiccamaro

I'm thinking of doing a 9" myself. The stockers are pretty lame strength- wise.
Currie has a mounting bracket to weld onto a 9" housing, don't know if it would work on the 8". Actually, using the Currie 9" bracket set up would be welding bracket bolt tubes onto the steel of the 9" center section of the axle housing, not on the cast iron of the center section.

The mounting bracket is actually an intermediate piece of plate cut to conform to the shape required with the bolt bosses welded to back edge of it. It has to bolt to some tubes welded to the axle housing because you need to be able to remove the plate to change out the center sections. Then it has weldments on the front edge that mate up with the torque arm.

I already have squirreled away stock third gen rotors, calipers and brackets, stock lower control arm, spring perch and panhard bar mounts to weld onto the 9" housing.

All of this is definately not impossible to do, but will require fabrication, fitment, welding and at least a medium mechanical skill level to accomplish.

I've also thought about converting over to a three- link set up. The torque arm rear end in our cars is actually a modified version of a three link rear with a different stiff, lower and longer top link. So all of the stuff is already there except for the top link and it's mounts on the rear end housing and forward and higher on the car somewhere. You'd need to check out the engineering for the required top arm placement, length and angle.

It is very probable that to properly mount the forward pivot for the top link, you would have to cut into the floorboard area roughly between the two back seats. Additional bracing to the existing frame from the top link mount would definately be required to handle the loads on the top link. I've heard of people that had structures with a drive shaft loop with the forward top link mount on the top of the loop.

I have a few tools like torches and a MIG welder, and my car is a low- dollar play toy with a spotty interior that isn't my daily driver anyway, so I don't really mind chopping things up and modifying stuff. That's part of the fun to me!

rjmcgee

I think the center sections are cast steel. I know I welded my axle tubes on my 10 bolt. Still would take some work to make a secure weld on torque arm mount.

lil tp1983

what is the difference between a limited slip and posi because my limited slip one wheel spins then both wheels spin & if i put a 3:42 gear in the rear end would it make the limited slip a lot better? which is better 3:42 or 3:73 i ride the express way just not a lot. can somebody help me out

customblackbird

iTrader: (15)

do you have pics of the weldable tq arm mount!?! this would be amazing. still i dont kno how to weld cast iron/steel or watev, but this bracket could be perfect. what is the part # etc. i would like to keep the tq arm since i just installed the jegster short tunnel mount tubular tq arm. and since i would prob be rebuilding the ford 8.8 that i get (if i were to get one) and sumhow mounting up the stock 3rd gen brakes.

i wont be going more than say 600-650hp with my car. bulding a 383 HSR with about 480hp at the crank, and prob gona juice it with a 100-150shot. for ***** and giggles. but the ford 8.8 is strong with 33 spline axles etc... they said it can handle more than the 12bolt. thats an option now for me. if u can post pics or a link to this weld tq arm mount for the housing.

Hallsresto.com

The 8.8 swap is no harder than swapping in a non bolt in 9 inch..in my opinion it easier....the thing to do is forget about the torque arm and weld in a crossmember for the upper control arms and relocate the lowers to match the camaro spacing...this will allow you to ditch th torque arm,, the panhard rod as well becouse the triangulated upper controk arms limit side to side movement just as the panhard rod does...no need for both...this frees up exhaust space etc as well as a side effect...earlier mention of the mustangs quad shock does not matter..the quad shock is merely a wheel hop dampening shock that mounts front to rear on 5.0 engine equiped fox mustangs,,,4cylinder cars carry the same suspension but dont have the quad shocks,,plenty of 5.0 guys remove them for tire clearance..so no need for them....and yes the 8.8 is ever bit as strong as a 12 bolt....they are basically the same design...12 bolt is 8.875 ring gear..and 8.8 is well 8.8 ....its a cheap swap thats not too hard in my opinion...i see them used with upgraded gears alot for $400 or less....

customblackbird

iTrader: (15)

whats different when welding cast iron compared to mild steel? different welding material? say i was to TIG,... what rods would i use etc.

lil tp 1983... the posi is a limited slip... they are the same. as far as gear ratios it depends on what u want and how u drive. the 3.73 will give u better off the line but will limit ur top speed and cause u to run higher RPMs on the highway hurting ur MPG. better for racing/drag racing etc.

the 3.42 is still a tall gear compared to a stock 2.73 or 3.23/3.27. this will hurt ur MPG less than the 3.73s do and lower ur highway RPMs when compared to the 3.73. if u want best gas milage 2.73s are best, a good medium if the car is daily driven alot is the 3.23/3.27. stepping up to the 3.42/3.73 would hurt MPG but give u better acceleration for a strip car etc. depends on what u want and how u want to drive the car.

lil tp1983

THANKS A WHOLE LOT

Apeiron

The temperature needs to be controlled when welding, cast iron wants to take any opportunity it can to crack.

customblackbird

iTrader: (15)

so then i could use the mild steel rods that i have? they are the S70-6 i believe.

91blackrs

any pogress???

customblackbird

iTrader: (15)

look in my thread down alil in this section. there are great links and info there. im set on doing the ford 8.8 swap but welding to the case isnt really an option. i have come up with a design that will be a bolt on.

gregsz-28

iTrader: (1)

There are torque arm kits for fox Mustangs with the 8.8", maybe you could buy one of those, and modify the arm to bolt to a third gen.

jamon8

iTrader: (3)

this is the fab board

anything is possible

you know what I really dont like too much

people who have never tried something and tell you that you cant

customblackbird

iTrader: (15)

sry its in the drivetrain section.

gregsz-28... yea there is, the guy who makes them is helping me in my thread. still tho its a great peice. i already installed a jegster shorty Tq arm so i will be adapting the ford 8.8 with my custom bracket for use with stock type style tq arms.

yea i kno what u mean jamon. haterrrrssss lol. unless u were saying i was the one saying u cant do something. welding to cast iron isnt a strong bond compared to being casted in, cast iron welds can be easily broken if not done correctly. cast iron can be welded but a really good welder wouuld be needed. and not something i would take a chance on being that its such a critial part of the rear suspension and that if it fails u could die. im all about doing things that everyone says not to do. which is why i do everything myself to be unique and different

lil tp1983

Does anybody know what the stock rearend size is for a 92 rs some say its a 7.5 i need to know this before i order my gear and does anybody know whether it matters what brand gear to buy?

iroc a 86 berli

this is a fabriction board, you need to find out wich axle your car is equiped with, there are a few diff ones that came in these cars. first fig out if you have a 10 bolt, i think the 9 bolts are in the irocs and z's. check this thread/sticky to find what your looking for.

https://www.thirdgen.org/forums/tran...-10-bolts.html

BIG_MODS

iTrader: (9)

I think the 8.8 is a very good choice for an axle. It is much lighter than a 9" or 12 bolt, and is strong.

Cut off all the old brackets and make new ones for your LCA and panhard bar. I made my panhard bar bracket adjustble using clamps from Lefthander Chassis:


For the TA: I wouldn't weld anything to the cast iron that will see significate stress. Strategically placed through bolts with nuts on the back side would be better. Seal them with silicone. Try for 3 places, top, middle, and bottom like I did on this Aluminum center section on the axle I built:





You'll have to have re-drill your wheel stud holes for the chevy bolt pattern, or use adapters from Skulte.com. If you don't do custom spacers you'll also have to check the brake/wheel pilot diameter to make sure everything will fit.

Might as well use the 8.8 brakes, hopefully they are disk.

Its a big job. Make sure you have some fab skills. Attention to detail is important.

More info on my axle can be found in my website www.f-bodysport.com

customblackbird

iTrader: (15)

wow big mods thats a nice setup... got anymore pics etc. the bracket u made for the center section is for a tq arm? did u make your own tq arm and thats what the rod ends are for?

i can only see like maybe 3 spots where uve attached the bracket to the housing. i would think more mounting points to deal with the stress of the bracket with a tq arm mount.

BIG_MODS

iTrader: (9)

You can see in the pictures the top bolt, and the ones on the bottom. The third spot is the rib in the front.

Yeah, I made a decouple TA http://www.f-bodysport.com/decouple_torque_arm.htm