Plastic PCV valve vs Metal PCV valve?

Bewy said

The actual valve itself is metal in both cases. The 'plastic' is just a 90* elbow that has been added for hose routing.

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I am sticking with the plastic PCV valve for now as it provides more forward air flow and the check valve to stop back flow has a better seal. It is interesting that the hose from the air cleaner to the oil cap is larger than the hose from PCV valve to carb with the PCV valve reducing flow further.