Power disc to manual disc.

There is a difference in master cylinders from what I understand. Atleast its that way from the factory. I know atleast B and E body manual brake cars got a plate on the firewall to renforce the metal there for in increased load onto it due from the manual brakes that power cars did not have. And you will need an adjustable or factory manual brake pushrod.

I'm currently doing this to my 72fish with a late model alum master and 11 3/4" discs...