WHAT MAKES WATER COME OUT OF BOLT HOLE ON INTAKE MANIFOLD .GMC 350

I see - “RIGHT AFTER CHANGING INTAKE MANIFOLD” .. Tell us exactly what was done.

Sounds possibly like the Water Pump may be leaking. Can you bring over to shop so that we can further diagnose that for you? Thank You, Char

You have can coolant passage in the intake or it can be a bit higher and appear to come from there. Pressure check to replicate if possible or take in for an engine antifreeze leak diagnosis. Take care Orr Automotive