I wouldn't use the SN95 prop valve on your car. It creates more headaches than it's worth since the SN95 prop valve went metric, and I believe bubble flare. Use your original combo valve, and just gut it and install the prop valve plug.
Plug your factory proportioning valve with this 5.0 Resto direct fit Mustang Rear Disc Conversion Proportioning Valve Plug!
lmr.com
The MC depends on what brakes you are actually using. 94-98 GT? 99-04 GT? 94-98 Cobra? 99-04 Cobra? Once you pick the MC, you can pick the appropriate brake line conversion from Max Motorsports that will connect your prop valve to the MC
Once you know what MC you will need to match the brake, you can buy the adapter lines here
Brake lines need to match the calipers. MM and other vendors make plenty of options for what to use. I'd list some but unless you specifically state which brake setup you are using, it's easier to wait.
Parking brake cables are these. You'll need two. They connect to all SN95 rear disks
Finish off your Mustang five lug conversion with these vital e-brake cables for rear disc brakes!
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Center cable? I don't believe there is an option for 79-86. I think you are stuck with the OEM cable and handle