I had my runners off yesterday doing an injector swap and I noticed inside the manifold port, which leads to cylinder #2, there was a small pencil-sized hole in the bottom of that port. I had to take a second glance to make sure it was a hole(maybe I'm seeing things). Is this a factory hole? If so, what is it for?

'91 TPI 5.7L

 

I think if you look closely, you will see one in each runner.

EGR feed I believe.

Mine weren't as big as a pencil, more like a pencil tip.

 

Yeah. I just found this pic of what I was trying to describe.