7.5 to 8.8 swap Q's

axles and brakes are the same, shocks are the same... if you dont have the frame mounts for the quads, there's no way to mount them anyway..

you dont even need to unhook the brake lines, just hang everything out of the way with some wire.. the only thing you cant use is the brake line tab that bolts to the rear cover.. I just left it off on mine..

As long as you're swapping the rear axles, do a 87-88 Tbird Turbo Coupe one.

Auto trans Turbo Coupes come with 3.73 gears and manual Turbo Coupes come with 3.55 gears. I choose 3.55 since I do more highway driving. Both ratios have 10.5 disk brakes with vented rotors as standard equipment.

It takes 2 guys the first day to get the old rear end out and the new one bolted in place. It takes 1 guy another whole day to do the brakes.
You will need a several sets of fittings, I recommend that you get them from Matt90GT's website, http://www.svo73mm.cjb.net/. Read Matt's instructions thoroughly, everything you need to know about the brakes is all there. You need to be patient and follow all the internal links, and there are many of them. You will need 2 fittings in the rear to adapt your old brake tubing to the TC disk brakes. The fittings go between the steel tube and the caliper brake hose. You will need another set of fittings to make a 2 port to 3 port adapter. To make life simpler, just buy the kits from Matt. You could piece them together, but it's not worth the time unless you work at an auto parts store with all the fittings ever made.
You will need to drill the quad shock mounting holes 2” below the holes drilled for the Turbo Coupe mounting points. The bolts are metric, so don’t loose them or the nuts. A 15/32” drill should be about the right size unless you have access to metric sized drill bits. Going without quad shocks is not an option unless you have aftermarket parts to soak up the wheel hop.

You will need a proportioning valve, Summit has one for $40 + shipping.
You will need a kit (FMS makes the part) to gut the stock proportioning valve, Summit also has that, about $10.

You will need a new master cylinder, see Matt's site and make you choice. I used a 94-95 Mustang master cylinder. Note that rebuilt 94-95 Mustang master cylinders do not come with a reservoir. That means a trip to the junkyard and some more money spent.
Your brake pedal may be very hard and almost impossible to lock up the brakes. I had to replace the front calipers with 73 mm calipers from a 91 Lincoln Mark 8 to get the braking performance up to par.

Bleeding the brakes will require 2 people and some coordinated effort. I don’t recommend using you wife or girlfriend to pump the pedal – they get offended when you yell at them. I used a homemade power brake bleeder constructed from a garden sprayer and some fittings from Home Depot. It cost about $25 and was worth every penny.
See http://www.mustangcentral.net/tech/brake.html for help with the emergency brake - the stock setup tends to lock up and not release properly.

All in all I have been very pleased with the results.

The rear shocks were different on mine. I just swapped in some 5.0 shocks. And I welded the quad shock mounts too.

lemme just get this straight, jrichker ur talkin about a rear disc brake upgrade right? is that necessary if you just want to swap differentials? thanks, cuz im gonna get my '84 up to 8.8" as well and will need the same advice.

BlahBlahson said:

lemme just get this straight, jrichker ur talkin about a rear disc brake upgrade right? is that necessary if you just want to swap differentials? thanks, cuz im gonna get my '84 up to 8.8" as well and will need the same advice.

Click to expand...

Only if you want the Turbo Coupe rear end. An 8.8 from a later model Mustang will fit as the other guys have posted. Of all the fox bodied Mustangs, only the 93 Cobra had an 8.8 with disc brakes.

See http://www.svo73mm.cjb.net/ for more info on the brake & axle combinations you can do.

If your decent at working on cars, this can be done in a day, easy.

The turbocoupe rear end is great, that is what I have, although I didn't want the rear discs from it,...too much hassle to upgrade, so I put the drum hardware from my old rear end onto the turbo coupe rear. the turbo coupe rear discs don't make much of a stopping change anyhow.

might look a little nicer through some 5-spokes tho eh? and what exact parts do you need to swap in an 8.8? just the diff and housing or do you need more?