HELP with master cylinder 4 wheel disc

For those that have done this I'm looking for help on what master cylinder to use
I have power brakes - 73 + disc on front + Right stuff disc on the rear.
prefer 4 bolt but not a must no high dollar mc---thanks

I see where some are using the mc from a 85 fifth avenue with the adapeter plate
and they say it works good ?????????????[/QUOTE
And how are your brakes with this setup? I just went through this on an E body. Those rear calipers were junk on the caddy's in the 80's. Probably the worst brake setup possible. Stick with the rear drums if you want cheap brakes.

I norminally and prefer using rear drums but I bought a Dana 60 for this project that came with disc brakes so it's a learning experience for me I'll see how it works out but I see no advantage