on my 68Dart I went manual with 73 disc brakes
I used the MP 4 bolt to 2 bolt alum adaptor plate with a 79 RC alum 2 bolt MC
IMHO the 2 bolt alum MC works better than the 5-6 rebuilt 4 bolt MC I had been useing
I did the same thing on my 88 truck,made an alum plate with 4 bolt holes to bolt it to the firewall and 2 holes for the 2 bolt alum MC that was on my vac booster
the alum 2 bolt is the same for power or manual IIRC
you need to do the homework on the MC bore size and the rear wheel cyl bore size to get the pedel feel you want with it
I had the big bore MC with big bore wheel cyls to give a good firm pedel,I liked it hard to mash myself and got used to them right off the bat
my car stoped as fast as it went after the swap with out locking the tires up on a hard panic stop