Your master cyl should be ok if running the 2 piton calipers and rear drums still if it's a stock dual master cyl such as the coupe had.

I've run a stock 11/16 master with stanza, 200b, twin piston sumitomo and now 4 piston sumitomos about to test out tomorrow.

All with either h145, h150 or current bw68 rear drums set ups.

As for the rest, not sure what spacing the 280z run that meets the ball joints.