I bought it with valve covers that have two breathers on one side and nothing on the other. I plan on adding a hole for my Pcv on the drivers side where nothing is at and probably a catch can before the intake. What I’m curious about is if I should leave the two breathers on the one side or if I should go back to stock with the breather for the crankcase coming from the air intake.
The OEM PCV system has been "closed" for decades. The first half-dozen years of PCV systems were "open". The difference is that the open systems used a breather that vented to atmosphere, the closed systems vent into the clean side of the air filter, or had a separate air filter in the air cleaner housing.
Point is, air gets filtered before it enters the crankcase, picks up fumes and moisture, and is then evacuated into the fuel/air stream in the intake manifold.
Under normal circumstances, that's the flow path--clean air from the air cleaner area, into the crankcase, into the intake manifold via the PCV valve.
But what if there's too much blowby for the PCV system to evacuate? In that case, the open system vents those fumes to atmosphere, which is EEEEEEeeeeevil. The closed system vents those fumes into the air cleaner--which is then drawn into the throttle body and then into the intake manifold bypassing the PCV valve.
Either way...the fumes are drawn into the intake manifold and re-burned.
Therefore, you need a PCV valve and plumbing into the intake manifold, arranged so that the fumes are likely to be distributed evenly among all the cylinders. On the
other valve cover, you need plumbing allowing fresh, filtered air INTO the crankcase. (And allowing excess crankcase fumes into the intake tract under heavy throttle or when the engine is worn-out.)
What filtered air? It's PCV . Look at the hose routing.
The fresh air that enters the crankcase
has to be filtered. As said--sometimes by the regular air filter, sometimes by a smaller PCV filter located inside the air cleaner.
Look in the service manual to see where the fresh air is sourced--after the MAF seems very likely. And that will also show you where the PCV plumbing is connected at the manifold, so it's distributed evenly.