Attached are a few photos of power brake boosters. This one is a factory assembly with vacuum line to intake manifold.

Factory power brake booster with vacuum line

This one is an aftermarket assembly from Classic Performance Products with the six lug disk brakes on the front and factory drums on the rear. This setup required a proportioning valve due to the pressure differential between drum and disk brakes.

Classic Performance Products power brake booster with proportioning valve

Hopefully, this will give some ideas about some of the available applications.