rocker breathers??

[69coupe]

Guys,
With a new motor I have a one tube from one bank which goes to the carby base. But the other rocker also has a hole. What does this connect to - a breather or can it be blanked off ??
Does the engine equalize pressure thru the heads :confused:

Would appeciate any advice

[anychevy]

One valve cover should have a PCV valve to manifold vacuum and the other should have a breather cap ? Or a breather hose to the carby base to help relieve crankcase pressure, the heads have little to do with it.