After reading tons of threads about 8.8" swaps, I'm still left with some questions. My first question is why more guys don't swap in SN-95 rear ends, instead of TC rear ends. By swapping in one from an SN-95, you'd get bigger brakes and a 5 lug pattern out of the deal. Where as Fox Mustang 8.8's are about 2.5" narrower than T-Bird 8.8's, the ones that were installed in SN-95's are from what I read, only an inch narrower than T-Bird 8.8's.
What's the story on this? I'd love to hear from anyone in the know.
I put a Mark VII rear end in mine. It's about an inch wider than the T-bird/Cougar rear. It's five lug disc brakes. And the reason that pushed me over the edge.... I had a Mark VII parts car so it was basically free.
Because of Mark VII rear ends being an inch wider than TC rear ends, doesn't that make it difficult to find rims that will facilitate 245, or 255 width tires? I thought one of the main reasons why a lot of people swapped in Mustangs rear ends, was because they were 2.5" narrower; thereby making it easier to install wider than stock tires on your car.
The 8.8 read housings between a stang and a tbird cougar are the same. The difference is made up in the backing plates and the axles.
I found that out from doing my search. I'm just talking about these rear ends as a unit (as-assembled dimensions). Instead of having to piece together a rear end that has the qualities and dimensions I want, I'd rather buy one that already has the dimensions and qualities I'm looking for.
I guess it depends on the rims that you want to put on the car. I have 235/55-16's on Mark VII rims and I have a ton of room on the inside and outside. If you're trying to run a rim with very little backspacing, then I guess you could run into problems, but the fronts are closer to the fenders than the rear, so you would have problems there first. I am more than satisfied with how easy it was to swap in the Mark VII parts. I even used the stock parking brake cables. I don't think you can do that with a TC rear. I don't know about the SN-95 parts so I can't comment there.
I have a Fox Mustang 8.8 housing and Fox length axles in my 83 Bird. The tires are 275/35/17 on a 17 X 9 rim with a +24mm offset. Now for a different comparison I have an SN95 width 8.8 under my Fox Mustang and it has 255/17/40's on stock 97 Cobra wheels (17 X 8 with a +30 mm offset). The only reason I mention that one is that if the SN95 rear will fit under that car and clear the 255's it will do the same thing on a T-Bird with the right wheels.
If you have access to the SN95 rear then use it. You will be able to use wheel spacers (1/16" thru 1/4", more than 1/4" and I would suggest longer studs) and offset to get the wheels and tires you want under the car with the only physical limitation being the wheel well itself and even that can be mini tubbed if you just have to have some W I D E ass tires on the car.
With all of that said, be sure you have the brake system handled if you are switching over to rear discs but as many of your posts as I have read I would think you already have all of that covered.
Darren
Thanks for the good feedback Darren. That's just the info I needed. I've been kicking around the idea of running 255's up front and 275's out back on the Blackbird, but I want to be able to rotate the tires.
It's good to hear from someone who's swapped in an SN-95 rear and mounted 255's on it. I was afraid of being faced with some kind of crazy back spacing issue. Seeing that you've been there, done that, is a big relief.
Thanks again for the feedback.
Just to make sure, the SN95 rear is in my 93 Fox Mustang Coupe car not a T-Bird. However, having the Fox Mustang rear in my 83 T-bird and having had a Fox Mustang rear in the Coupe I am 100% sure the SN95 rear will work in a T-Bird with the correct offset on the wheels and/or spacers.
Another note, I am running 17 X 8 with a 30 mm offset on the front of the Bird and I would not push anymore than a 245/40/17 on that wheel combo but I do have the SN95 96+ spindles up front which will push the tires out an additional 8mm per side so if I was running the 94-95 SN95 spindles a 255/40/17 would most likely work.
Darren
Hey; thanks again for the feedback Darren. That's gonna be good info to have when I'm ready to start doing all this. I hate flying blind.
275/40/17s will rub the wheel wells with a Lincoln rear end.
I had to put air shocks in to keep from rubbing.
(http://i233.photobucket.com/albums/ee79/daminc/85%20Vert/IMG_6615.jpg)
now it sits like this
(http://i233.photobucket.com/albums/ee79/daminc/85%20Vert/IMG_5344.jpg)
I was thinking about running 275's out back on my "Blackbird" (my DD '87 Sport with black side moldings), but I'm planning to run 255's on all 4 corners so I can rotate the tires. It's a daily driver, so I want to get some good use out of whatever tires I mount on it. My "Red-Winged Blackbird" though (black '88 TC with red stripe down both side moldings) is definitely gonna have some beefy meats hung on the back of it though. I just might hang something wider than 275's on it (tweaking will be required of course). My "Red-Winged Blackbird" received a V8 transplant mind you.
I like your car's stance by the way. :)
I have zero room left in the wheel wells with the 275's in my 83. If I rolled the fender lip and relocated the rear coil overs I might squeeze a 295 but its just not worth it to me. A set of good drag radials in a 275 would most likely stick all rwhp the car has anyhow.
Darren
If I roll the lips in the rear I will be ok I think. It barely catches the outer 1/2" of the tire....I will probably do that before I start any filling and sanding back there, just to be safe.
I was told to use the same size tire front and rear for rotation purposes,but,the tires are unidirectional,so,I thought it was basically pointless to do that,SO,I went with 275-40-17 out back, and 255-40-17 up front. I may go with 315's out back on the next pair of tires.....maybe. The 275's are pretty wide,and without the quad shocks,and,using 2 1/2 in tail pipes,no rubbing anywhere.
Actually , I know people who still do and have had no trouble............. But according to the instructors from Hunter alignment products the radial belts are more pr0ne to separating if the rotational direction is changed ... That was taught to me back in like 89 or 90 when the dealership I was working at got a new alignment rack and I had too spend 4 days in class learning how to use it . Since then I have always just front back rotated , tire technology may be different now though so I could be outdated in my thinking ,
But it works for me :hick:
You can't do the "X-pattern" rotation on unidirectional tires. They are made to turn one direction. Now,if you want to pull the tires from the rims,remount them for the opposite side,re-balance everything,then sure. I'm not going through all of that.
Also,I like the larger tires out back. I want the widest tire I can fit,yet still look "right". 255's are as wide as I can fit up front with no rubbing at all. I'm pretty sure I can go to 295 or 315's out back with no issues.
Rotation for the Sport is not an issue I concern myself with for the Sport. Never have.
I also have larger wheels out back...17x10.5 as opposed to the 17x9 up front. That also dictates a lot for the Sport.
Well , yes that would make a really big difference ;)
I am wondering if the 87-88 cars have a different rear wheel well than the 83-86 cars, anyone? I cannot even see how I could stuff a 305 under my car without mini tubing the car and that is something I am still considering.
Darren
Yes Darren. The rear wheel wells on 83-86 Birds are just about the same width as Fox, Stang wheel wells. The rear wheel wells on 87-88 Birds are wider. They afford you the room to hang 315's if you have rims with the proper back spacing. You still have to remove the quad shocks though. On a Bird that's been lowered, more modifications might prove necessary.
Like Vinnie, I too have plans of mounting 315's on the back of my "Red-Winged Blackbird."
i found that a fox 8.8 is cheaper then the next style up rear and there are more to come by. just make sure its a good one the one i got was out of a 91 and it had 3:08 and posi after a month it started to sound funny then a few months later it was making poping sounds it was in the car for about 7 months b4 it really started raising hell so i decided to have it rebuilt and it was destroyed inside posi disks were shatered and parts got up in the pinion bearings and took them out gears were wore. so if you find one make sure its low miles find out how it was driven or if you want to be safe have it rebuilt. mine has new every thing except for the carrier and axles
I was able to get an SN95 rear end out of a 95 GT and it was $175 brake to brake. They were nice enough to include the ABS sensors without cutting the wires and the soft lines to the calipers. This has been an average price from what I have seen on the Mustang boards. These rear ends are the same on the GT's from 1994 thru 1998. In 1999 the overall width increased and the housing got wider as well as the axles getting longer. The housings on the 86-93 GT's and the housing on the 94-98 GT's are identical. What is different is that the axles on the 94-98 GT's are longer to accommodate for the ABS sensors and exciter rings on the axles.
With all of that being said if a person wanted to use an existing Fox 8.8 rear but convert it over to the 94-98 GT/V6 rear disc brakes (they are identical as are the axles) but keep the track width of the Fox rear you would want to use the caliper brackets under SN95 and brackets only:
http://www.northracecars.com/Brakes.html
The GT/V6 rear brakes are more than adequate for our cars and are very abundant in the salvage yards which makes them pretty cheap to install. They also have the brackets for the Turbo Coupe rears and the Cobra rears. I have their Cobra brackets on my 83 Bird and the quality and fitment is really good. One thing you will need is a set of the hubcentric rings with the SN95 brakes if you are going to use Fox style 8.8 five lug axles like those in a Ranger pickup. This is due to the rotors lining up on the axle hub which causes them to be hubcentric. The hub on the Fox style axles is smaller than the hub on the SN95 style axles thus making these adapter rings necessary. These guys have them here:
http://www.discbrakesrus.com/make/ford/hardware.htm
The flip side is if you are going to order a set of axles then just order the kit from North Race Cars which includes axles that are the Fox length but have the SN95 style hubs.
Darren