Restoring my braking system.

['86 5.0L]

I picked up some Raybestos 6060R rotors to replace my cracked ones, I figured I might as well do the whole 26 year old system. so along with the front rotors what would you recommend to replace as well?

Master cylinder?
Brake booster?
rebuild the calipers?
replace the lines? stainless steel lines?
what brake pads?
wheel cylinders in the back.
what drums and shoes?

Im perfectly happy with the stock system, might do the 87+ setup in the future(definitely not right now). its just for a 100% street daily driver,

[MAD MIKE]

A system that has old brake fluid the seals will be acclimated to the old fluid. When the system is opened, or flushed the new brake fluid will have different properties from the old. New fluid will not be compressible like the old which will create higher system pressures. Combined with the old seals being affected by the new fluid, can cause a leak at a seal.

Master cylinder?

If the bore is fine, clean it and install new piston seals. Otherwise replace.

Brake booster?

No need to rebuild/replace this unless it is no longer working. If the MCs rear seal was leaking the brake fluid will damage the boosters bellows.

rebuild the calipers?

Seals, bolts, and bushings.

replace the lines? stainless steel lines?

If they are old(there should be a date on them), replace them. I think Russell sells a line kit for the 78-84/87-93 I4 'metric' calipers. Be aware that Russell's QC is hit or miss with the fittings, some are not completely machined/threaded. '85 GT (7.5" dual exhaust) and '86 GT(8.8" dual exhaust) are two separate bastard year cars when it comes to brake hose kits. Not sure if anyone sells a kit for those two years.
If you plan on upgrading to SS lines and '87-'93 5.0L front spindles/brakes in the future(being you have a 8.8") you could purchase a SS brake line kit for the '87-93 5.0L and install the rear line now. And use rubber lines up front. When you install the 11" rotor/spindles you can then just change your front hoses and be done with it. Centric/StopTech are quality brands.

what brake pads?

The early style brakes have limited performance pads. A set of Raybestos PG Plus are fine for a daily driver.

wheel cylinders in the back.

Rebuild or replace. But since it takes the same amount of work to rebuild and they are relatively cheap, replacement is quicker.

what drums and shoes?

Use quality brands such as Centric, Wagner, Bendix, Raybestos.

Avoid anything by Brakeware brand. These are bottom dollar buggers. In a pinch I was stuck using their brand for a couple of hoses on my S10. One hose internally leaked, the other one blew itself off the crimp swedge fitting.
Not the best feeling when my normal commute was on Oak/Fell streets in S.F.

MM does have its brake upgrade kit for the stock '87-'93 5.0L Mustang, or an early car with the 11" front brakes and 8.8" from a '86-95' car.

Hawk brake pads (HB-263 HPS)
MM High Performance Rear Shoes
MM Stainless Steel Caliper Sleeves
MM Stainless Steel Brake Hoses (3-hose kit).

['86 5.0L]

Thank you that was exactly what I was looking for, I picked up some Raybestos PGD310M pads.

[JACook]

The early style brakes have limited performance pads. A set of Raybestos PG Plus are fine for a daily driver.

Porterfield makes the R4S compound pads for the 10" front discs, and R4S 9" rear shoes.
Not a knock against the PG Plus, just pointing out there are performance alternatives for
the 10" discs.