That is the all the good Dr. Diff's handiwork. '71-2 rear housing with his 10.7" disc brake swap. He can give you better details, but IIRC, the calipers are Mustang Cobra rear calipers with the incorporated cam-actuated parking brake. Discs are off a late '80s Toyota Cressida/Supra (same exact discs as on my '86.6 Supra) with the register bored slightly to fit the 8-3/4 axle. Discs have the inner drum for the parking brake on the Supra, but I've found it's pretty ineffective on my Supra, even though adjusted properly and shoes have plenty of meat.

Custom parking brake cables supplied by him with the kit, but built by another vendor. Hook right up to the existing e-brake cable at the frame rail attach points.

Had the fronts before I purchased his rear setup.
But matches to front fairly closely, according to
Cass. The fronts are 1st gen Viper calipers on the brackets built by AR Engineering, bolted to A-body drum brake spindles. M/C is a MP unit, 1-1/32" diameter bore, IIRC, (maybe 1-1/16"). Haven't driven the car yet, as kids and jobby-job occupy most of my time, but pedal is firm and travels an appropriate amount of distance to reach firmness, for my taste. Whether it stops well without two feet on the pedal, I have yet to determine. Prop valve is an old Direct Connection adjustable unit, for nostalgia's sake.

Sorry for the hijack...