So comparing the factory PCV 'flap' vs these Amazon/E-Bay/etc. specials, it's pretty clear from my testing that even though these line up with the spring, they don't actually do anything. I mean side by side comparing the innards of these PCV systems, they don't even look alike:
These PCV repair kits do not work at all for our engine. I have tried 3 of them with the SAME result. I didn't notice ANY suction nor pressure release from any of them. I needed to know more so I gutted one of the PCV caps out to see if it's actually doing anything. I ripped out the 'flap' from the second kit I tried, removed the factory PCV spring and popped it back into place. Guess what? The squeal came right back when I did a warm start. I felt nothing coming out of the vent nozzle. I popped off the cap again and just didn't understand how this is possible. Is my PCV not the only issue? It was ripped but this doesn't make sense. I decided f-it, let's drill a hole in the middle of the cap. I did that and guess what? Squeal gone.
This gives me a lot of faith that the Vargas valve cover will in fact work just fine while eliminating the factory PCV system. I ordered another one of these PCV kits, didn't drill a hole in the center cap=still working but I get a tiny amount of PCV creak when I'm in 1st gear and zipping though a parking lot, just as the engine goes into vacuum and only for a half a second tops. I am going to drill a series of tiny holes directly beneath the vent nozzle which sit underneath a relief cap which I am confident will be enough to block crap from coming in but be adequate in releasing pressure. I'll update when done.