From what i read, for a pbr dual piston brakes and rear disc sn95 setup on a tbird, i need to get a master cylinder for a 93 cobra with a brake booster. Am i correct, and is there alternative master and booster combo that could work
You need a master cylinder with a 1" bore. Typically everyone gets the 93 Cobra unit as it has a 1" bore and the Cobra booster pretty much just bolts up to the existing holes in the fire wall.
You can use the MC and booster out of a 94/95 GT Mustang or the MC and booster out of a 94-98 V6 Mustang. The issue with either of these is the booster has a different bolt pattern so you have to drill a couple new holes. Pain in the ass, ask me how I know. The MC is a 1-1/16" bore but they work fine.
So, my suggestion would be to run the '93 Cobra gear as it makes life a lot easier. Either way you go you will need the following:
3 to 2 kit (to take your existing 3 port MC to a 2 port design)
Manual adjustable proportioning valve
Stock combination valve plug kit - used to gut the proportioning side of the combo valve (have to do this to make the manual adjustable proportioning valve work correctly)
Brake adapter fittings - you can use these or build your own lines with the correct metric fittings (pain in the ass)
To to recap, you will need the booster and MC for a '93 Cobra, a 3-2 kit, a manual adjustable proportioning valve, and a stock combination valve plug kit to install the MC with metric threads.
I thought you can also run an MC from an 85 lincoln towncar. Those only have 2 ports; front and rear.
Rock auto had the master cyl and booster available, i purchased it, plus i make my own brake lines, i have a donor 98 mustang gt, i will try the stock combo valve on that first since im using stock brakes, if i dont like it, ive used cpp adj proportioning valves before on a 65 mercury comet i had, on that i had quad piston brakes on the front and stock drums on the rear with no booster and could lock up all 4 wheels
The '85 Lincoln TC MC is a two port design MC with SAE threads and a 1" bore so yes you can use it. It is a direct replacement for the 83-86 cars being the MC is SAE threaded on these cars but some do not like it due to it having the look of well an 80's car. The '87-'88 cars moved to the same MC's as the '87-'93 Fox Mustangs which is a three port design with Metric threads and a 7/8" bore. The '93 Cobra is a three port design with Metric threads and a 1" bore and is more modern in its design and appearance.
I will say that the original '85 Lincoln TC MC is aluminum and can be had for a whole lot less money than the '93 Cobra MC especially if you get a remanufactured one.
I have trashed brake lines trying to get a stock combination valve off a car. Sounds like you have done this kind of work in the past so just take your time and use lots of PB Blaster or the like a day or two ahead of time.