1967 and newer dual master,,,parts store like napa,,,dont buy any cheap junk,,were talking brakes here,,,,,make sure you get a master cylinder for your application,,,,drum front /drum rear or disc front drum rear,,
also you wil need a im going to speel this wrong i know it,,,just took some tylonel pm,,lol porportioing valve,,several vendors carry these,,,or you could put an adjustable valve on your system,, i use a disc/drum with a 15/16 bore master cylinder from mopar performance,,with a adjustable poportioning valve on the rear brakes,, car stop on a dime,,,,i also use dot 5 silicone brake fulid,,,and have been for 15 years,,for a car that doesnt see every day driving,,,the silicone brake fluid will not collect moisture like regular brake fluid,,,also if you have a leak for any reason it wont take your paint off,,,