In the past when i had abundant time, i would do anything to save a buck, but spending $120 on drum brakes you have to pull yourself seems pretty steep, especially rusty ones that need half the stuff replaced.
You can piece together a disc setup via rockauto for under $200. Easy. Hell Speedway sells one for $350 complete for a 8 3/4.
If you do want to keep drums. I have some 10 inch ones and some 11 inch ones for a 8.75.
Also have whatever comes on a running, driving 1977 8.25. Would let them go for a song if needed. Lmk.