Your local auto parts store has stock replacements for the brake booster and master cylinder unless you are doing a concourse restoration. I used these parts and I'm satisfied.
The nipple on the intake manifold in front of the carb connects to the air cleaner. The nipple on the base of the front of the carb (the throttle body) is for your distributor vaccum advance.
The transmission and brake booster both get their vaccum source from the rear of the carb. The brake booster pulls its vaccum from a relatively large diameter fitting on the back of the carb throttle body plate. The transmission gets its vaccum from a nipple on the back of the carb that is about the same size as the one on the front.
