I have a 70 Swinger and have been thinking the same thing, have you come across a thread outlining the conversion/parts involved? I have power drums/front disc. I guess with all the talk about master cylinders, bore size, lack of master cylinders, etc, Im just wondering what MC we should use.
What you should do is stop worrying about what size master to use and get that car out of your garage and into my garage, where I think it would look much better! Nice car!