Wondering if this is hurting me- or just ignore it as I'm not about to pull the engine right now. Have a relatively fresh 385 sbc and have noticed oil in the plenum of the TPI (FIRST) and not a small amount some time ago. I suspect a poorly running efi-engine break in may have washed the cylinders, or perhaps the Moroso 20206 oil pan (I think- never saw the interior of the pan there is two very similar looking versions). A catch can with another DD collects a nasty mix of water/carbon/fuel, on this engine it is collecting clean oil which could drained back to the crank case...I'll just keep an eye on it and empty at each service. Engine does not smoke, I don't notice much oil usage on the dipstick. I haven't tuned in awhile so it may have been an issue for octane tolerance which I thought at the time was leaning out, in a couple months will get it tuned by a pro and see what he thinks about knock with premium fuel, no audible knock- but that particular issue was before installing the catch can. Whats your opinion- what have you seen with incorrect PCV valving- still running GM 5.7L valve.