Where is the PCV on a 1977 Chevy with GM 350?

On a 1977 Chevy with a GM 350 engine, the Positive Crankcase Ventilation (PCV) valve is typically located on the passenger side valve cover. It's usually a small, round valve with a hose attached to it, leading to the intake manifold.

However, there's a slight chance it might be on the air cleaner base depending on the specific setup. Check both locations to be sure.