Mine was for 4 wheel power disc, but the kits shown are available for disc/drum or 4 wheel disc- you select which MC you want when you order the kit. My power boosted setup is a pleasure to drive.
I may not be understanding you correctly, but if you are looking to install a disc/drum manual MC, I would advise against it and get the power booster setup. The pedal ratio on the truck is probably not going to provide a very good pedal feel (high effort and/or very long pedal travel) for even a front disc only setup. Discs require more hyd volume and more pressure than drums.
Perhaps others here have gone with a manual disc/drum MC and they will post their experiences... manual drum/drum and manual disc/drum have different MC piston diameters and different MC piston pressure applied requirements... I am not a brake expert, but the results can be truly awful if you mix the wrong components.
Wish I could be more help, but I've only installed a 4 wheel power disc setup and a 4 wheel power drum setup on these old trucks...
You can order the MC only and select a 2 wheel disc setup:
$285 master cylinder with booster & proportioning valve
