6000 Vacuum Line

I Have A 86 Pomtiac 6000 2.8l Carberated. I Noticed The Other Day A Loose Vacuum Line. The Line Comes Off The Front Of The Intake Manifold(above Waterpump), Three Lines Come Off A That Point.the One That Gos To Towards The Fire Wall. What Does It Connect To? Where Can I Get A Vacuum Diagram For This Motor? Thanks For Any Help.