i have a drum/drum 70 dart. my master cylinder has a larger reservoir in the rear and a smaller reservoir in the front. does this mean when i do the disc swap up front i can keep the master?
Should be. Look at some pix on a site like NAPAOnline to idenify. The drum/drum MCs used the same sized reservoirs front and rear, AND the disc/drum MC will be taller than the drum/drum MC.
BTW, the rear reservior goes to the front brakes and vice versa.