Most people probably know this, but you need to make sure your new master cyl has the groove for the rubber retaining ring. Also. I had to shorten the pushrod as the pedal was too high. 318WR has this covered with his adjustable pushrod.
power boosters are generally really light. I want manual brakes just to save room under the hood and eliminate a vacuum hose.
Do you have a certain year master cylinder that has the groove? Which one did you use?