65 dart slant brake upgrade
If you go disks, you need a proportioning valve for the rear, so smart to change to a dual reservoir master cylinder when you re-plumb. Several disk kits work with your 9" drum spindles. Scarebird and Wilwood do, as I recall, and you can stay small bolt pattern with both, if you want. Scarebird makes you redrill stud holes in the new rotor, but 1/2 cost of Wilwood, even cheaper if you buy just their adapter plates and get the other parts (GM & Toyota) local.