Considered IRS but going to just build my 8.8...do they offer drop in 8.8 with 9" ends?

Here's the thing, let's say you are successful in making 800rwhp.
While that might be how much it makes at the wheels, most of that will probably never stick to the ground on the street.
With a stiff road race suspension it's probably never going to dead hook either, even at the track.
If you don't go to the drag strip, the reality is that 800rwhp is just a number on piece of paper.
I'd find it unlikely you break as set of moser 31 spline axles unless the car shakes or wheel hops, then you really start messing stuff up.
 
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It’s worth the peace of mind .

I run moser 31 spline Fox length axles with 94-04 flange for the disc brakes .
FRPP cobra 31 spline posi unit
94-04 gt rear brakes .
North race cars caliper backing plates to retain stock fox track width
So my rear cobra kit I’ll be getting from north race cars, which is who said I could upgrade to 31 spline. Idk what brand they would use in that case. Where did you find your spline Posi unit and is there a certain year or is it one of those fits multi year applications
 
Here's the thing, let's say you are successful in making 800rwhp.
While that might be how much it makes at the wheels, most of that will probably never stick to the ground on the street.
With a stiff road race suspension it's probably never going to dead hook either, even at the track.
If you don't go to the drag strip, the reality is that 800rwhp is just a number on piece of paper.
I'd find it unlikely you break as set of moser 31 spline axles.

Is there an echo in here? :p
 
Currently i run 18x10 with a 295 nitto nt05...hooks pretty good on the street right now without the torque arm in yet. I also plan to widebody or flare so i can fit 18x12 with a 315 or 325 at some point. Ill get a set of custom wheels so i can choose my offset when the time comes. I like to plan things out and think of my end goal so when i spend the time and money it fits into my final plan and i hopefully dont have to do it again. Sometimes i know it happens (like with my 2.5" exhaust which ill be upgrading again to 3") This car being my first major build, over the last 7yrs of working on it myself ive learned alot. Ive done a ton of work to it already and ive spent more than i thought so far... (maybe an up-to-date parts price list isnt a good thing to keep around all the time lol)
Started in a carport at a house i rented, got married, and finally got a house with a tiny 1 bay garage (better than being outside lol)...house projects have taken away my time and cashflow for the fox but now ive decided its time to make some progress on this. Giving myself 3 years to get what i want hopefully. Usually i have the car reassembled every spring so i can drive it in the summer but ive decided that , if need be, i keep it off the road for a few years to get it done right its worth it.
Getting all my plans and part lists together so i can start buying parts as the budget allows.
 
Currently i run 18x10 with a 295 nitto nt05...hooks pretty good on the street right now without the torque arm in yet. I also plan to widebody or flare so i can fit 18x12 with a 315 or 325 at some point. Ill get a set of custom wheels so i can choose my offset when the time comes. I like to plan things out and think of my end goal so when i spend the time and money it fits into my final plan and i hopefully dont have to do it again. Sometimes i know it happens (like with my 2.5" exhaust which ill be upgrading again to 3") This car being my first major build, over the last 7yrs of working on it myself ive learned alot. Ive done a ton of work to it already and ive spent more than i thought so far... (maybe an up-to-date parts price list isnt a good thing to keep around all the time lol)
Started in a carport at a house i rented, got married, and finally got a house with a tiny 1 bay garage (better than being outside lol)...house projects have taken away my time and cashflow for the fox but now ive decided its time to make some progress on this. Giving myself 3 years to get what i want hopefully. Usually i have the car reassembled every spring so i can drive it in the summer but ive decided that , if need be, i keep it off the road for a few years to get it done right its worth it.
Getting all my plans and part lists together so i can start buying parts as the budget allows.

Sorry about my ignorance about your setup, but assuming you're running centrifugal supercharger then? I would still assume full throttle in 1st and 2nd would produce spin with your setup but maybe you have your rear setup really well (those NT05's work really well also, I've always ran NT01's which don't hook straight line as well). Either way, doesn't sound like your dumping the clutch and chasing 60' times which is what's going to break stuff.

I'm with you on planning stuff out, I hate buying stuff twice. I've always been a big advocate with setting a goal for your project and THEN planning it out. Just diving in with no goal in mind and you start having to redo stuff as your goal turns into a moving target.
 
Sorry about my ignorance about your setup, but assuming you're running centrifugal supercharger then? I would still assume full throttle in 1st and 2nd would produce spin with your setup but maybe you have your rear setup really well (those NT05's work really well also, I've always ran NT01's which don't hook straight line as well). Either way, doesn't sound like your dumping the clutch and chasing 60' times which is what's going to break stuff.

I'm with you on planning stuff out, I hate buying stuff twice. I've always been a big advocate with setting a goal for your project and THEN planning it out. Just diving in with no goal in mind and you start having to redo stuff as your goal turns into a moving target.

Yes i have a vortech. Wide open for sure 1st and 2nd are useless but if i feather it a little i can def hook pretty good ...i have 3.73s which i dont care for to much. First and second go so quick and with my HP and cam setup it makes town driving a nuisance. I heard alot of people liking 3.55s or 3.27s. Ill go over my build with whoever builds the rear for me and see what they recommend for my setup.
 
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Talked to Moser...$4500 + shipping for the 8.8 with 9" ends built for 800rwhp, posi with 3.55s, diff cover, 5/8 studs, powdercoated, and wilwood brakes, :eek:...about $1k more than i was hoping.
 
Anyone recommend any shops or other places to get this done or buy a drop in unit?
As it has been stated at the top of this page....Big HP numbers are only relative when it comes to putting it to the ground. It's always been a point of contention with me. Everybody goes out and decides that they need 700+ Hp on the street, and build an engine combo capable of doing it. Then, after spending the money to do it, drive the car to and from the Saturday night cruise-in.

And never fully realize the power.

All 700 HP will do is spin a tire that much harder, make that much more smoke, and put the engine against the rev limiter that much quicker. Until you decide that you are really gonna compete with the car in an arena where either you couple that power to the track at the jump (drag racing), or let that dog eat in some "Silver State" style top end speed contest, the money you spent to take the car from where it is now to where you wanna be is a bunch of wasted dollars.

But it's your wasted money, you are free to do with it how you see fit.

If you are building the car as a streeter (which you have said that you are) a 31 spline 8.8, with a T lock or better diff, is out there already to drop in your car in a JY.
It'll come with 5 lug 28 spline axles and the accompanying differential. It'll already have disc brakes. All you gotta do is find an SN 95 Gt.

As for the axles, gears, girdle, and differential upgrade. Strange, Currie, Moser, North race cars, as well as a multitude of drag race fabricators (Racecraft, Wolfe) can supply you with the rest of the stuff.
The brakes can be upgraded using OEM Cobra stuff, and sourced from Rock Auto.

I'm guessing that you want the 9" ends installed to eliminate the C clip eliminators that you'd have to use instead,...but again, I'd ask why? I'd bet 90% or more of the guys here that are making big power and use the eliminators, or that are still using C-clips. And scores of Chevy boys with their 10 and 12 bolt rears doing the same. Axle breakage where C clip eliminators are necessary are mandated when you are repeatedly beating the thing on a dead hook traction surface at a drag strip........ period. All else,..is because you prefer the peace of mind. A c Clip eliminator is a DIY mod. A 9" end is not.

And you are not building the thing for that. A T/A, and PH bar and heavy front and rear sway bars are X cross/road course mods. If you build the car for X cross/road course, It will suck as a drag car. Throwing a rear set of sticky tires on an otherwise stiff suspension car set up for going around a corner, will be less than optimal at the strip.

Read: Hooking hard enough to break an newly installed, aftermarket 31 spline axle will be pretty unlikely.

If you just have to have a serious duty rear that you can buy that will fit supplied as a unit, you already found the guy that will do it for you. (Moser) If you live in a big enough market where there is a race car fabricator then you take the car to them and they charge you a similar amount of money and will keep the car for a couple of months or more to do it. (just search for other threads where guys have left their cars in chassis fabricator purgatory).

Or you save yourself the money, Buy a JY 8.8, Do the rest yourself, use C clip eliminators if you have to, and save yourself about 3 grand.
 
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I'm with mike on this one on the use of the car and what you really need.
IMO, i'd build the entire car first then do a custom rear if needed.
You are guessing you want 3.55's. 3.55's and 3.73's aren't really very far apart.
Then you couple it with the fact that you are adding 300rwhp and honestly, the change will be negligible.

My rear was built by my buddy about 20 years ago, That's a 31 spline moser axle setup with an old school auburn (not rebuildable) and it's put up with my abuse for years, that includes my early 20's when it was my daily and I had no respect for mortality.

It's still in my car which makes quite a bit of power from 2000rpm to 6500rpm
I've almost never driven on anything other than drag radials since they were invented.

Here's my take, add the discs, an 03 cobra locker (which can be had dirt cheap new), change all the bearings, keep the gears (for now) and do moser 31 spline axles.
Then if you "need" to build something, do it after your engine is done. You don't know what 800rwhp is like, so you really can't make the gear choice now, nor do you really know how it's all going to work with a widebody and what is sure to be either a very very limited wheel choice or custom wheels.

None of these parts will go to waste if you do it twice.

In my mind, a $4500 rear is an insane price for something not really necessary.
 
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thank you for the detailed replies. i definitely see what you are saying and it makes alot of sense. when i say im a little OCD about overbuilding stuff im serious about that. it sometimes hinders me from enjoying what i have and leaves me in search of going way overboard. for instance...my car currently made 514rwhp on the dyno with stock bottom end. i detuned it slightly to 490rwhp and fattened up the tune at WOT to hopefully save the block, for as long as possible anyways. now i dont beat on my car, but i do engage in some seriously aggressive street driving from time to time. now in the back of my mind i know i have to watch my rpms and not go all out because the block might split at any point at my HP levels so in my mind i really should have a dart block. the T5 wont hold long so i should have a tko or a t56. the fuel system could use an upgrade etc. well if i do a dart why not take advantage of it and go to 750 or 800rwhp. when i redo the fuel system and trans they can handle it. and so my build goes up to a more extreme level but i feel likes its not done properly if the block is always in jeopardy of splitting and it leaves me feeling that i did a less than perfect job. (if that makes sense)
I have an overall goal for the car which would be a higher level show quality foxbody. i have alot of custom stuff ive already built and plan to do to take it to that goal. i just want the car to be built to the level that it should be to handle those goals. if my stock block could be made to hold 600rwhp comfortably and take a decent beating that would be great. I definately am not made of money by any means but this has been a long time goal of mine. i appreciate the feedback on these forums because it saves me from alot of mistakes i may have made otherwise. again, this is my first big build. im incredibly detail oriented which is a curse sometimes and makes my jobs harder then they need to be.
i basically want a fast, reliable, show quality streetcar (not asking for much right? lol). i want the engine, drivetrain, suspension, and brakes to compliment each other and hold up to aggressive street driving for when i feel the urge to do so. car is only driven in nice weather.
i currently have cobra discs all around. once i install the k member and TA and new coilovers my suspension is pretty much done. was looking at either glennsperformance or BBRC fuel system and -AN lines. I just sourced a low mileage Cobra rack. I will do custom wheels when everything else is done. i might widebody or flare so i can fit a 18x12 and a 315. i dont want to mini tub.
I would love to not have to spend so much money. everyone says t56 the tkos are garbage. have to build a dart to hold the power etc. so i feel thats what i should have if its a superior product. im still learning and dont plan to tackle the rear and undercarriage until next winter so im trying to get all the info i need in the meantime so i can buy the right stuff. If 31 splines and a tru trac will are a proper setup for me then when i pull the rear out ill have it built and powdercoated but if i should do more i want to do it at that time.

to shorten my rant up.. a good all around street suspension, 600+ rwhp engine and whatever block i need to handle that (dart), transmission to back the motor up (t56 or tko), fuel system, brakes (have cobra brakes but might go to wilwood or any recommendations?), better steering setup (03 cobra) and stout rearend (8.8 with whatever parts are necessary)

sorry for the long response, just trying to explain my inability to do a less than "perfect" job.
 
I'm a believer in 600rwhp is about the max you need/want in a fox and even sometimes that number is excessive.

The trans will also have a determining factor in the rear since most of them have a different 1st gear ratio.

Nobody seems to take into consideration that foxes have no traction control, anti lock, stability and they weigh roughly 3200lbs.

I've been in 600, 800, 1000rwhp foxes on sticky tires.
It's still like being in a 400rwhp fox on a set of 600 treadwear pepboy tires with 100,000 mile warranty.

Keep in mind everyone that I know that has taken it too far, just leaves the car in the garage, they either don't want to crash it, don't have the room to stretch it's legs or they don't want to damage the show finish on any parts.

My advice, build your project for enjoyment and not vanity...
I speak and an ex-vanity type that was into numbers (not so much into perfection on cosmetics).
 
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The ford explorers came with 31 spline posi trac 8.8 rears in the late 90s....into ( I think ) the early 2000s. In the independent suspension models. They arent hard to remove....and easy to build.

On the IRS....the thunderbird of the mid 90s had a carrier identical to the cobra IRS....except it was iron....and stronger than the aluminum one. I know you aren't going IRS but thought it was a decent piece of info.

Im with you on 315s some people actually get that tire size under a fox without tubbing at all. Im shooting for 335s with flares.

My car is untuned and puts out more power than the road can absorb. Seems like you're already past that level too. An old man told me that the sweet spot with a fox, on the street, is around 350- 39?hp. He said more than that would take the fun out of the car because the needed tire wont fit withought serious mods. With my car I'm starting to think he was right.

Steve, will get a chance to go over some more logs...and I'll get some more time in the seat. After that....who knows what I'll believe about the subject.
 
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The ford explorers came with 31 spline posi trac 8.8 rears in the late 90s....into ( I think ) the early 2000s. In the independent suspension models. They arent hard to remove....and easy to build.

On the IRS....the thunderbird of the mid 90s had a carrier identical to the cobra IRS....except it was iron....and stronger than the aluminum one. I know you aren't going IRS but thought it was a decent piece of info.

Im with you on 315s some people actually get that tire size under a fox without tubbing at all. Im shooting for 335s with flares.

My car is untuned and puts out more power than the road can absorb. Seems like you're already past that level too. An old man told me that the sweet spot with a fox, on the street, is around 350- 39?hp. He said more than that would take the fun out of the car because the needed tire wont fit withought serious mods. With my car I'm starting to think he was right.

Steve, will get a chance to go over some more logs...and I'll get some more time in the seat. After that....who knows what I'll believe about the subject.

That reminds me of the biggest limitation of my favorite non-fords. I've always loved this GM body.
1522373523648.png

This little car is so freakin' plain. Boring lines, boring interior, the thing screams econo box. You can't even get a 9" slick on these things w/o moving the leaf spring hangers inboard.
But,....Once you do that...then the car turns into a monster of it's own...
1522373756422.png

Kinda reminds me of a certain Orange car..... Thinkin' wheels like these are in it's future.
You gotta mini tub most any car when you wanna put a big tire on. I have 315's on the Monster, and everything fits under the car. I'd rather go under a car before I'd cut a fender or add a flare..Flares died in the 70's when there wasn't anybody making axles for the rears, and the only thing that you could do was push the wheels out.
1522374109260.png

I'd say the lines hanging under the car are the airshock lines......N-50 15's = AOOAP

Ass on a plate.
 
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That reminds me of the biggest limitation of my favorite non-fords. I've always loved this GM body.
1522373523648.png

This little car is so freakin' plain. Boring lines, boring interior, the thing screams econo box. You can't even get a 9" slick on these things w/o moving the leaf spring hangers inboard.
But,....Once you do that...then the car turns into a monster of it's own...
1522373756422.png

Kinda reminds me of a certain Orange car..... Thinkin' wheels like these are in it's future.
You gotta mini tub most any car when you wanna put a big tire on. I have 315's on the Monster, and everything fits under the car. I'd rather go under a car before I'd cut a fender or add a flare..Flares died in the 70's when there wasn't anybody making axles for the rears, and the only thing that you could do was push the wheels out.
1522374109260.png

I'd say the lines hanging under the car are the airshock lines......N-50 15's = AOOAP

Ass on a plate.
Are you sure about the T-Bird IRS? There are lots more T-birds in the J/Y than 2003-2004 Cobras, and the parts would probably be cheaper too.
 
Are you sure about the T-Bird IRS? There are lots more T-birds in the J/Y than 2003-2004 Cobras, and the parts would probably be cheaper too.
The cars I was referring to have no room for a tire of any kind. I wasn't talking about any IRS, I was talking about lack of space for a big tire, and what I think is the best way to accommodate it.
 
On the IRS....the thunderbird of the mid 90s had a carrier identical to the cobra IRS....except it was iron....and stronger than the aluminum one. I know you aren't going IRS but thought it was a decent piece of info.

Mike, I think he was referring to this statement that sickfox made.