Drums to disk swap, small to big rotors ?'s

An all drum brake master cylinder has equal size reservoirs for both the front and back. The disk brake master cylinder has a much larger reservoir for the the disks on the front. The addtional volume is needed as the pads wear the caliper piston moves out and the internal volume increases. With drums the adjuster opposite th wheel cylnder makes up the clearance as the shoe wears and the pistons stay in the same relative position.

It will work if you don't swap but you will need to be topping up the master cylinder all the time.