[Kracka]

Have you tried just removing the catch-can setup all together for a test? My guess is going back to stock routing would cure the problem (PCV to IM, VC to intake). You can leave your check-valves in place, as long as the ones you got can flow a decent amount of air they shouldn't be the restriction.

The only other thing I can think of is your piston rings not sealing well. You just did drop-ins, right? Have you done a compression or leak-down test yet?