Disc Brake Master Swap & P valve Question

Okay, got all the disc brake stuff off of the '73 Dart yesterday. Going to clean it up, rebuild it and prepare to put it on the '71 Dart.

Thought I'm having and have a question about is this:

'71 Dart has manual disc brakes on it now. Swapping to get larger bolt pattern to match rear swap I did.

'73 Dart is a power disc brake car.

Instead of swapping the power disc brake assembly off the '73 as a whole onto the '71 (going to be wife's car so considering power brakes for her) will the existing '71 Manual Disc brake master cylinder work as is?

'71's existing brakes are the 4 piston older small bolt pattern ones of course.

How about the valving? As it was a disc drum car to start with can I leave it alone or do I need to swap the '73 Dart stuff over?

Thanks for any help. I looked through a search (perhaps did not use the right terms), but did not really find any definite answer to this issue. Most everything I find is on going from drum to disc.

Cheers