Review on Spectre Performance 5333 Breather Grommet by Mark Sutovsky

Excellent quality, both have pre-cut bottoms. The one for the PCV valve, you just push a little bit with your finger and it opens the slit. Once you do this, it will always open in the vacuum. My only problem was the air intake. Too long for my 327th hits rocker arm. The one for the PCV valve is amazing. Too bad they are sold at different depths. Just poke with your finger.