^^^^^. Both the lower breather canister and the oil fill cap are often ignored. The caps easy, the canister is a PITA. But that’s the place to start.
There’s numerous articles on open and closed PCV systems here and at yblocksforever. Done with the valley pan and the oil breather. That’s the best long run solution, but the intake usually has to come off the remove and modify the valley pan.
If you get into the rear seal, check out Ted Eaton’s article on that at
https://www.eatonbalancing.com/2008/...-y-and-others/