I did the PCV mod. Had a spare valve cover. Gave it a go. Amazing difference. Pulled the spare off with a claw hammer. Plucked it out easy. But you can’t do this when it’s in the car. In the car, use visegrips. Put a thick cloth over. Lock the grips, twist back and forth and pull. They are in with dob of Red thread lock. To get the PCV hose off, there’s a tab to use. Press in? Out? Can’t recall. I checked out the Camaro forum. They say 5/64ths and 7/64ths are the drill sizes to use. I converted that to 3mm for the top hole and 2mm for the bottom. Soaked the valve for a few days (forgot about it) Throttlebody cleaner evaporated. Left this muck It (the wrecker spare) was clogged solid. Couldn’t see through. Heaps more came out after this. Did many many soaks and cleans. Got it super clean. Drilled the holes. After this, getting the straw on the throttle body cleaner inside the valve was easy. More schmutz came out. Bits of carbon. Easy to get the metal out after drilling. Another soak and in it went into the VZ. The one that came out was ok. Not clogged. Could see through it. Didn’t expect anything to happen. However each day, the idle and revs smoothed more and more. Always has trimmed revs as you drive. The tacho gauge just twitches up and down. Bugged me. Not anymore. It’s pretty much steady as now. Vacuum seems better. Why?? Smooth acceleration. Smoother than Barry White walking in yogurt. Would recommend to everyone. There were no changes made or fuel added during this change. I take it the ECM has been slowly relearning fuel trims now the crank case gassed are flowing better. I didn’t get any data before hand. Will be doing this on my VE Calais now that the VZ is super happy with it. Again, it was a pleasant surprise. This came from my VZ one (much cleaner) Fuel consumption improved as well.