The problem with drum is stoping quickly at highway speed. Drums worked OK for me for 30 years. Now I would alway want at least 73 Duster/Dart front disks. Non power disks require a lot more pedal effort
I have a 67 notchback with an 8.75 and I have 10 x 1.75 rears. They also make 10 x 2.5. I have a complete 10 x 2.5 but I have not installed them because my car stops good with the 73 duster disks on the front.