Valiant to Duster disc brake/rear brake swap

If you replace your lower ball joints you need to order the ones for the disk brake application or use the ones off of your disk brake donor. I can't confirm this but someone told me recently that the '73-'76 10" drum brake lower ball joints are the same as the disk brake ones in those years. So measure before just changing parts out have a part guy look them up. You can run manual disk brakes but you either need to buy a manual disk brake master or remove the residual pressure check valve from the port going to the front brakes from your drum brake master, or use the donor car master. Modifying your drum master nor using your power disk brake master is ideal as it will make brakes more difficult to apply. The manual disk master cylinders have a larger piston in them to make brake application easier when not power assisted. You should use the proportioning valve from the donor car also. Drum brake cars just have distribution blocks and are not "proportioned". Rear end will bolt right in but there are two different rears with BBP, a 7 1/4 like the one in your 6 cyl Duster and an 8 1/4 heavier duty one which will require shortening the driveshaft. Your donor car could have either so check to avoid surprises.