I’ve used this grommet with baffle in the valley cover, worked fine with a stock motor. With the next stroker motor and supercharger, it wasn’t enough and I have to go with a welded baffle. It was solid on the side facing the distributor, the gear was apparently throwing enough oil at high rpm and boost that I picked up oil beyond what the rubber baffle could handle.
https://www.moroso.com/pcv-grommet-b...-package68772/