i will go to a parts store and hopefully they will have one with a grommet and pvc valve kit ?You need to get the correct one before you start drilling. Al the aluminum covers I ever owned had knock outs. But that was back in the 70's. They might be different now.
How do you screw them in without a hole? Confused!I purchased these screw in breathers for my MP covers. They are screw in and incorporate a pcv on one and a breather tube on the other. I got these so I wouldn't have to drill the knockouts.
Chrome Breather & PCV Caps for Mopar Performance Valve Covers Small & Big Block | eBay
Interesting. I'm not a fan of the look but personal choice there. The knockouts are exactly that. You can pop them out with the ball end of a ball peen hammer.They screw in the hole for the cap. Scroll to the last pic.
They're made for MP covers so you dont need to modify the covers OOTB.