disc Brake conversion

I am about to start my DBrake conversion (finally). The rear end is done so It's time to get started. My 65 will be moving to a 68 KH set up. I have the Dbrake spindles,calipars,rotors, hubs and backing plates. I will need a master cylinder and a prop valve.
Anything else I need to know? I am pretty sure I can retain my ball joints leaving them in the A arms and just bolt the DB spindles on since they are pre73. do I need to go larger Ball joints? Advice is always golden here.