The axles are longer. Turbocoupe is 3/4" longer than a stock fox body rear end and Mark 7 is 1.5" longer than a fox body. Turbocoupes do have an 8.8 rear end. Its the same rear end used in the 93 cobra. I think the auto turbocoupes have factory 3.73's and the 5 speed ones had 3.55's.
5 speed turbo coupe rear ends are 3.55 but they are not the same as a 93 cobra there are differences
The rear end will bolt in and work fine in a fox body. You do have to do some mix and match of brake fittings and e brake cables and drill quad shock holes if you are still running them. Here is a basic list of how it goes.
In short, yes the 88 TC will bolt up... I dont know about using the 88TC stuff to swap to 5 lug so I wont answer about that at all...
But to make the 88TC rear work, you need to read this: (79-93 4 Lug Ford Fox Body Mustang Brake Upgrades)
These are 4 lug 10" vented rotors. This is a great swap if you can find the whole rear end! It is a 8.8" rear end, and the stock gear ratio is 3.55 for the manuals, 3.73 for the autos on the Turbo Coupes, and 3.08 on the 93 Cobra. Keep in mind the axle is .75" wider than the stock Mustangs, you will need to adapt the brake lines fittings. The easiest way is to use the drum brake rear hardlines and adapt at the caliper softlines. You need to drill the quad shock mounting holes 2" lower on the T-bird axle for the Mustang. For E-Brake cables, you need to purchase use the FMS cables. If you have a '93 vintage, you need to use the '93 Cobra cables. Ford made the '93 E-Brake cables like the Sn95 units with a center mounting in the tranny tunnel. 93 Cobra E-Brake cable #F3ZZ-2A635-A.
If you cannot get the whole axle or do not want it, get all the brake lines, calipers, bolts, rotors and axles. Then swap this into your existing axle. Here is a parts list that you need to do the swap from the '87-88 Thunderbird Turbo Coupe or '93 Cobra:
* 10" 4 lug vented rotors * rear calipers * rear caliper brackets * Axles -- if you use the stock caliper brackets. They are 3/4" wider than the stock '87-93 units. * soft brake lines * (2)FMS M-2809-A ebrake cables for '87-92 cars, '93 Cobra units for '93 year cars * (1) FMS M-2810-A center Ebrake cable * FMS M2450-A proportioning valve solid end cap * Adjustable proportioning valve * new 2 port 4 wheel disc master cylinder (1" bore for stock front calipers or 1 1/16" for the 73mm fronts) * 3-2 port master cylinder conversion. Click here to Order * 2 adapter fittings to use the stock drum brake hardline with the softlines
