I know a very old post but recently ran into an issue with a leaking twist in grommet on my valve cover which connects to my pcv. The valve cover hole has these tabs which require a twist in grommet. After much research the only grommet I could find was a Scott Drake C7AZ-6892. This grommet does fit but not very tightly. Had a fair amount of
oil leaking around the grommet after driving the car. The valve covers do have baffles. Home Depot to the rescue with a Danco #18 O-ring. I fit over the grommet between the lower tabs and upper tabs- reinstalled and now no more leak. Just wanted to provide what worked for me as I would think others with the twist in valve cover hole may run into a similar issue.