I have seen people still asking ? about PCV set up so I’m going to make one more post about it so can understand how external PCV routing using Dual catch cans works and how you must have it setup to work properly, below the diagram showing as well PCV is actually two separate systems with unique faults and deficiencies. There is a low-pressure system low side, that works under vacuum or low pressure conditions idling, light acceleration, off the throttle, And there is a high pressure system, high side, that works when under boost or load. if you do not have high side check valve on the high side it will suck in hire and pull it through the crankcase so when whenever you’re on idle, the check valve on the low side will open and the crank valve on the high side will close so that way it does not suck in hire when the crankcase is under vacuum so if you do not have check valve on the high side it will suck in hire and pull it through the crankcase and then you will have a massive vacuum leak . If you just have low side catch can only with no check valve and you vented to atmosphere only you will have excessive crankcase pressure and then you will end up haveing smoke out the exhaust . so if just have check valve on the low side you will be fine when idle and Port throttle but you will have smoke under Boost You have to have all both sides just as how factor valve cover has both it’s very important that you do that So for the plugging of the head ports reliability and cleaner valves .but after that you going need vacuum release valve .This is way you who’d need to install a Vacuum relief valve allows you to dial in your crankcase vacuum to the precise level like 10 14 so you can seal your system with no fear of pulling too much vacuum through the system. If you do not regulate the vacuum, on your system, You can pull too much vacuum and damage seals .. as can see in the diagram there is vacuum relief valve