I'm sure this has been beaten to death, but think about this.
83-mid 85 had the narrower rear end(same as mustang)
mid 85-88 had the wider rear (approx 1" each side)
looking at my 86, sitting next to an 83, they are identical bodies.
No noticable difference in relation to the tire/fender.
another thing... The tires/wheels didn't change backspacing.
So, a couple questions
1) where did the inch go?
2) technically if we use the narrower "mustang" rear or 83-mid 85 cougar rear, there should be no clearance issues, just that the wheels will sit slightly inboard.
Since I'm working on my new project cat, I'm attempting to get all my info straight, then start hitting the junkyards. Eventually, I'll have my stroked 302 (347) done and will install it with a MAF HO EFI system.
It didn't go anywhere.....
The axles are the same length, the housings are different.....the track width is the same.
There you have it.
If track width is the same, then why does everyone make a big deal about swapping rear ends?
In that case I can go ahead and install a 8.8 mustang posi rear end in and it should fit with no change to the track width, coorec?
Incorrect....
Actually why don't you be a bit more specific about what year Mustang rear...
If you swap an entire
FOX-Mustang rear axle (as in everything from drum to drum) it will be narrower. The housing would be the same width as the 83-85.5 7.5 rear housing, but the drum to drum width would be different due to the longer axles.
You need to take the time and do a seach on this subject and read the two lengthy threads already discussed on this subject, instead of going through all of it again.....
Track width is drum to drum. You said in your ealir posts that track width stayed the same......
Problem is, wording.
A rear axle is what rotates in the housing. Takes 2 for a complete rear end assembly. When people talk about a rear axle, sometime they mean the axle, other times they mean the complete assembly.
According to http://www.coolcats.net/tech/general/axleinfo.html the 83-85 cougars shared rear end assemblys with fox chassis mustangs.
if this is so, and track width didn't change, then all fox chassis mustangs/capris/cougars/and t-birds are interchangable.
We know this to not be true. Something is missing.
I have pics somewhere on this forum. The only thing that changes is the housing/drums. The 83-85 share the same HOUSING as Fox Stangs, not axles.
Found it. http://www.foxtbirdcougarforums.com/showthread.php?t=4484&page=2
Do you understand the words that are coming out of my mouth? Yes, you are missing something. You aren't reading well enough. I NEVER said the track width was the same between the Fox Mustangs and the TBirds.
The HOUSINGS are the same between the 83-85 Tbirds and the Mustangs/Capris/ et al. (This applies to the 7.5 for the above TBird/Cougar years only). The 8.8 used in the Fox Mustangs and the 87-88TC's is the same as well.
The AXLES are longer in the TBirds/Cougars, even though the housing is the same width.
THUS the track width is WIDER in the TBirds/Cougars due to the longer AXLES.
The 86-88 7.5 rear HOUSINGS are wider than the 83-85 and Mustang ones, but the AXLES are the same length as the 83-85. Thus the overall track width is the same for all years TBirds.
Um, Chuck:
I can see how he'd be confused with that. I'm assuming is that you mean the 83-88 T-Bird/Cougar track widths are the same as each other, but not the same as the Mustang. A little clarification ;)
Bird/Cat axles are DEFINITELY wider than Mustang axles, as I found out much to my dismay when I was replacing the axle shafts in my old Cougar. The junkyard sent Mustang shafts because, according to them, "they're all the same". They weren't.
I clarified it....but this has also been discussed ad nausium...twice....
well, this is the information I read, from cool cats.net
Beginning with the 1983 model year, the Cougar and Thunderbird shared a common-width 7.5" rear axle with the Mustang/Capri. Therefore, all 4 cars have the same rear end
this was cut/pasted directly from the site.
then what Chuck W said in the second post
The axles are the same length, the housings are different.....the track width is the same.
But yet again directly from cool cats.net
This rear end was used until halfway through the 1985 model year, when the Cougar/T-Bird got a unique width axle. It was approximately 1" wider than the Mustang unit and about 1" narrower than a Mark VII rear end.
time to take a measuring tape to the junkyard.
So far I've seen more contradiction than anything with no hard numbers. Which helps to explain why the subject has been beaten into the ground.
I'm not here to make enemies, I'm asking all this to hopefully get some good info. If I do, I could easily do a complete photo tech atricle explaining all the differences and interchangability since i have free access to a complete junkyard.
The axles themselves is what makes up the length differnece, not the housing
83-85.5 got the mustang width housing and axles
85.5-86 got the tbird width housing, but the mustang width axles
87-88 got the tbird width housing, and tbird width axles
If you want to use a rearend that is the same width, then try a 96 on up Mustang w/ 8.8 and disk brakes, they are a an inch wider than a fox 8.8.
I have a mustang 8.8 and I'm installing the god thing, track width be ed. I can't imagine that an inch or a fraction of an inch on each side will make too much difference in handling. So there!
It won't. I just didn't like the way my car looked at first. But it can pave the way for wider wheels in the rear. :)
NO......
First go back and read THIS THREAD (http://www.foxtbirdcougarforums.com/showthread.php?t=3664) There are measurments there, and in another therad that is referenced in that one as well.
This is how it is.....
ON the 7.5's
83-85.5 - Mustang housing - TBird axles
85.5-88 - TBird housing - TBird axles
87-88 8.8 - Mustang housing - Tbird axles.(same width (housing and overall) as the 83-85.5 7.5 set-up)
The rear track width on a TBird regardless of year is 58.5"
The rear track width on a Fox Mustang (SVO and 93 Cobra excluded) is 57"
Rear track width on an SN-95 Mustang (94-98) is 58.5"
The axles in a Tbird and SN-95 Mustang are 3/4" longer than the Fox Mustang stuff.
The ones who suffer from all the oddball problems are the 86-88 7.5-reared cars...due to the longer housings.
OK, here's a question...
What are YOU wanting to accomplish with what you have?
That would be a better way to go about this, instead of this continual rehash.
I take it by your screen name you have an '86. What are you wanting to do? You are stuck if you want to do something like install 87-88TC disks or the like due to the wider housing.
As has been mentioned, if you want something with the same track width, and disks, get a 94-98 Mustang rear assembly (complete).
What do you want to do?
Just for clarifications...the info on coolcats.net is for the housings, not the axle shafts. I purposely don't mention track width differences on the site because of the potential confusion.
Does a V-6 Mustang (94-98) have an 8.8 axle?
Nope, 7.5. At least not from the factory.
If an SN-95 mustang rear end is a bolt in solution, then problem solved. V8/GT rear end.
In the end I'm going to need a rear end to handle a reasonably built fuel injected 347 stroker motor. Since I'm starting with a daily driver car I have just purchased, I'll finish the motor and build a good AOD before I start. But easy swaps, like rear end, suspention upgrades (sway bars, ect) I can do in the meantime.
Since I want a limited slip, I'm stuck with an 8.8, no biggie since it's stronger.
Only reason I'm not doing all this to a mustang is because I'm tired of the higher insurance rates and all the cops that love to eyeball the mustangs, firebirds, ect. Besides, I also now have a usable back seat.
the sn 95 rear will have 5 lug obviously. youd either have to swap out axles, or upgrade the fronts to 5 lug...figured it would be worth mentioning...
also...
ive got the 8.8 TC rear stripped and ready for PC. i measured out my 5 lug mustang axles just to double check and there just about the same length as the turbo coupe ones from the face of the lug plate to the end of the splines...
the 7.5 is still in the tbird. i hadnt realized for whatever reason that the 7.5 might be a different in width compared to the turbo coupe rear diff.
so, whats gonna happen? is the 8.8 gonna bring my wheels even tighter into the car? i never liked how far they were inside of the wheelwell anyway. no biggie as i know it will work fine and i can go from there but now im curious....
If the axles are the same length, then how would they bring the wheels in further? ;)
Your track width is going to be the same as it was with the 7.5. That is ASSUMING the Mustang axles you have are SN-95...but you also stated they are the same length as what was in there...so....you should be fine.
cool,thanks chuck.. i meant the differance between the 7.5 thats on the car and the 8.8 with the sn95 axles... for some reason i never gave a though that the 7.5 could have a different track width than the TC8.8.....i never compared the 2, just assumed they would be the same.
The axle length and track width never changed on the Tbirds, and is the same as the early SN-95 stuff (I can't speak for the 99-04 stuff). You just can't use the SN-95 axles in your 86-88 7.5 housing, but you can use them in an 83-85 one (<---done it twice).
You're using rear disks correct? (just making sure)
yeah, M2300-K. i just dont want any supprises when it comes to putting the car together. im watching mansons progress cause im about to order the same front arms. heres my parts list so far:
turbo coupe 8.8/3:73
m-2300-k
che rear adjustable lowers, fixed uppers
new bushings in the housing
M-3075-D (2003 cobra front arms)
prothane or energy isolators/boots swaybar bushings, endlinks (did i miss anything?) etc
mustang bullit springs front and rear as well as tokiko dampaners
MM CC plates and SFC as well as your cross braces...thanks a million BTW....!
i hope everything works soundly together. im not looking to make the car handle like a race car, but as well as or better than say, a turbo coupe. i dont think i realy missed anything but if i did feel free to let me know...lol.also, if you would have changed anything i wouldnt mind some input. i think i have a relitivally decent setup there...with the 17x8s im playing it safe but they should be good enough for me.
i still need to order the urathane, springs and front arms. im afraid to pull the trigger on the springs and front arms cause of mansons trouble there. i have spindles from a 2001 cobra. i dont want to have to punch someone in the face...!
later on i want the upper and lower torque boxes re-inforced, and maybe rocker reinforcements. im also pondering a 6 point but i just dont see the car ever being fast enough to require one. they are sweet though and should hold the car together rather awesomly...
17x8 wheels with brobably just 245s all the way around
i realy hope
You shouldn't have any issues with the rear and the brakes.
Seems like the intelligent thing to do if you use the SM-95 rear would be to upgrade to 5 lug fronts also. Seems like there is a better selection in aftermarket wheels, not to mention the newer 5 lug mustang wheels. Also if you have the option of upgrading to rear discs, why would you not do it? Yeah, you need a different macter cyl and porportioning valve, but easy to get from the same donor car. Only other issue is parking brake and even that is almost always easy to solve.