With all the rear disc kits out there a person would ask why did you go to all the trouble of making your own brackets . Well I am cheap , For a reason . This truck is a play toy so spending a lot of bucks just isn't in the budget . It also help my motivation when someone tells me " That won't work " . Told a couple of guys what I had planed at work and that was the response .
That being said I can't suggest you do this with liability being what it is . I'm just telling you what I did .
After a bit of research I started in . Because this is a mudder I have to look at this with a different goal . Really no sense in buying new rotors so I hauled myself to the local junkyard . The front rotors off a 3/4 4x4 work great for this and I found a dana 44 already out of a truck (think it was an 83 ) . The rotor and hub assm are separate pieces on these axles .
Next I removed the rear hub and drum , Drove the studs out carefully because I'm cheap and didn't want to buy new . Tossed the drum to one side drove the studs back in once the rotor was cleaned up a bit . The studs were about 3/16 shorter due to the rotor being thicker than the drum at the mounting flange but were still plenty long enough to suit me .
While I was at the bone yard I gave 5 bucks a piece for the calipers . That way I had Cheap cores for the rebuilt calipers I bought later ( did I mention I was cheap?) . I was told that if I wanted an ebrake I needed to buy old an version Of Caddy eldo calipers but that was more money and you guessed it , I didn't spend extra for those . The calipers I bought were the same ones for the front axle .
The brackets were a time killer but I had a whole lot more time than money anyway . Drug home a piece of scrap 3/8 plate from work and with a cardboard template laid it out . Torched away the big spots and massaged the rest with a grinder . Did a ton of test fitting , measuring , checking for square . Tacked the plates on and checked everything again . Then welded them on . I Waited till the bracket was solid then marked , drilled and tapped the caliper bolt holes .
Cheapness still had a hold of me because the disc pads that were on that axle at the salvage yard were near new and I couldn't help myself , They went on that axle .
The only thing I didn't do was change out the proportioning valve . Instead I bypassed it . Big puddle in the master cylinder is plumbed to the front , the small gos to the back . Which seems to work good for my play toy .

The Old drums were always packed full . Glad to be done with them

I'm not sure if any weight was saved but it was sure nice to have effective bakes

I left the brackets pretty wide until the very end

Plenty of room with the wheels on .

You can see even with the thick mud it still stops .