I have a 75 280z and when I push the brake pedal the engine either revs up an additional 1000 rpm or almost dies. Anyone have a similar problem? Could the booster have a vacuum leak or could there be another leak somewhere else that is causing it?

Plug the fitting on the manifold and try it.

Need a new booster. My Z is a manual can I use the zx booster? I've read that it is too big for use with a manual.