hi i have a 65 chevelle and some day i want to put disc-brakes on the front but for now i have to use the drums up front. i put new shoes and wheel cylinders & brake lines on it this past weekend and they turned out to be pretty good! but i still have the single fruite jar master cylinder on it and i want to up grade to a dual cylinder. safety reasons .what cylinder do i need to buy to do this? im hopeing some body might point me in the right deriction on this. thanks alot scott.