0first of all a hydroboost setup does not use vacuum, its operated by hydraulic pressure from the power steering pump. if you are looking for a source for a hydeoboost unit this guy builds a very good unit. He was recommended to me by ECI an old friend and trusted brake supplier/
Im planning a LS engine in my truck and they dont generate enough vacum to run the power brakes properly.
www.hydratechbraking.com