Front "China wall" sealing issue on SBM

If I did go with the cork gaskets I wasn't planning to put silicone on the whole thing, just some globs in on the edges where the heads/block/intake meet.

Next time I run the engine I'll pull the PCV valve and breather from the valve covers and watch for how much blowby it has once it's warmed up. I'd hope not a ton, the short block I assumed to be high-mileage since it came out of a smashed-up 2000 Ram pickup at a junkyard but the cylinders still had significant cross-hatching left with no ridge to speak of at the top. The oil also looked and smelled fairly fresh and there was no sludge buildup anywhere inside so I'd like to think it was maintained well.

I'm thinking it needs a better (higher-flowing) breather as the one on it now seems kind of restrictive, it's one of the cheaper ones with the foam and a 1/2" or 5/8" fitting to go the air cleaner. Speaking of which I also need a proper air cleaner base with the fitting for the PCV breather, the current one just has a hole I've covered up with heavy tape and the breather is just open to the engine bay.

@dano the leak is only coming from the front china wall, not the rear. Fortunately the upper rear of the engine is dry as a bone.