Drained both oil and coolant and everything looks fine, that was the strange thing...

I will rebuild the engine from 0 just to be sure btw, forged internals and stock heads with upgraded springs. The car sees to much track time and it has some miles on the odometer now.

Oh, okay, now I've understood the question. Sorry but my english is terrible, and some technical things are difficult to understand.

If the radium kit doesn't include upgraded valves, then no, I'm running the stock one. Do you think that was the root cause? I'm not that mechanically inclined, I understand the basic things from a hw/sw point of view (I work in automotive but not the engineering part), but I let specialized shops do the work.

can be, change it as soon as you can

part number subaru: 11810AA141

The stock PCV isn’t designed for boost, so it will allow positive manifold pressure during boost to not only stop gases from venting out of the PCV, but air will also reverse into the crankcase and pressurize it more.

Signs of this are piston ring damage, lifted oil dipsticks, smoke from the tailpipe, fouled spark plugs, gasket seal failure so oil running down the engine, up to engine failure.

I think you are overthinking all off this.
Have you check any of this yet?
KISS

https://www.autozone.com/diy/coolant...ir-to-overflow

He is thinking this happened. His symptoms might be more specific than just having coolant overflow.

https://youtu.be/Z2paKA1fYGY

The 2nd torque after use will literally be torque to yield.

I believe they will need to be measured to see if they are in compliance/spec within the stretch/deformation grace length. Considering someone is running boost with high compression and is having issues and might be dodging a bullet, taking a chance on retorquing and clocking the bolts is risky. If they aren't to spec then they will need to be replaced. Do people reuse TTY headstuds? Yes. I doubt they are reused under warranty work. Just tightening the headstuds is enough of a project that it would be best just to do head studs. I personally would switch to ARP head studs.

“I would say it’s okay advice”

https://i.imgur.com/fEsIlDX.jpg

Wow, this is exactly what happened to me. Ok different engines, but looks like my problem.

@x808drifter
I wish it was something trivial like that... but I'm not that lucky, did all the tests ofc and everything was ok. Besides the car worked well for like 2 years, it's not a new build or something, so something happened.

I also don't like the 50/50 solutions like re torquing the heads. Also once disassembled, from my experience, you need to resurface the heads and the block and I want to have a look at the pistons just to be safe. I will rebuild everything just for piece of mind (forged internals, arp studs, upgraded springs etc.).
I don't like it since is quite expensive (I need to ship the car abroad and the labour costs are double from what I've seen in USA) but I plan to keep the car at least another 3 years and in the long run probably it's cheaper.

At this point I hope the heads/short are reusable and not dameged beyond repair bc finding a replacement could be a pta, but I think I'm ok since the car was still running and there was no sign of contamination of oil or coolant.

If your heads are bad then I have used ones for super cheap. They aren’t 100%. Just offering.

Good idea on the rebuild while you are in there.