66 dart disc brake ?

hey guys.I have a 1966 dodge dart 273 4 brl car. It has disc brakes in front, i have got new rotors, and some other things. Now im stumped. Do any of u guys know if there is a difference in the disc brake master cly? as apposed to the regular setup? Im looking thru Napa for a new master cly, but they only list a 1 inch bore single drum brake setup. As well as a power setup. Can someone help me on the org master cly part number? It is a single reservoir unit but it has a extra chunk ontop? sorry i dont mean to sound like a idiot i just wanna order the right stuff. thanks brake gurus...