This part replaces the factory pcv valve stopping airflow (and oil) into the floor of the supercharger on gen V LT4 DI engines (2015+ Z06 and Cts-V) 'Plug' version seals this path off entirely 'Port' version re-routes the crankcase flow to the outside of the engine, so that it can be used for external ventilation. Made in the USA! The LT4 PCV SolutionLimited stock available!This part replaces the factory PCV valve stopping airflow (and oil) to the supercharger.'Plug' version seals this path off entirely.'Ported' version re-routes the crankcase flow to the outside of the engine, so that it can be used for external ventilation, or with the MMS PCV can.For installation (approx 1hr), the blower needs to be unbolted (cover screws and center screws 10mm), and belt 15mm, and lifted about 3" for access. Some wires can also be unclipped for ease of installation.The stock PCV valve comes out with 14mm allen and the new part goes in with a 13mm combination wrench. I suggest using some oil to transfer the factory o-rings and for installation. Install 'horizontal' for blower clearance and for mounting barb fitting on 'ported' version'.This is completely reversible as needed; no hammering or gluing. One piece billet anodized aluminum designed and cut in the USA that cannot come loose inside your engine.Here is a pic of the part being installed, again you see the barb pointing straight up, that is where PCV air (and oil) is routed. On older / LS engine models this was piped externally which allowed us to do what we wanted (or needed) in regard to oil consumption.