I am running disk brakes on all fours, an 80 series master, and a booster from an 82 Celica. Backing spacer is from a minitruck. I had to go with the smaller diameter booster from the Celica because of space issues on the firewall of the early '73 fj40. I had to make no adjustments to the push rod.
'97 FZJ80 40th Anniversary - unlocked, 2.5" OME, sliders