What’s this Port For?

In the picture you see a small port in the middle of the head between the valve ports. What is this port for? When I pulled my Torker 340 intake the PO had blocked these off with a piece of stainless steel between the head and the manifold.

Not knowing what is was for but obviously there for reason, I left them open and the stainless steel pieces remain on the work bench.

Any idea's?

Author: Barfly