If you are worried about
corrosion between the blocks and other
hardware, put an insulator like
electrical tape under the part where it touches the
mast. SS doesn't have much of a problem with corrosion,
bronze definitely needs to be insulated from the mast. SS
hardware has been on my mast for over 40 years without an insulator and corrosion under the pieces is/was very very minor.
Ted-Gel, LocTite, Lanolin, etc on the threads of the fasteners will limit corrosion there.