Installed new valve covers, now have smoke/steam coming out from breather.

[Lil Ape]

I installed new edelbrock chrome valve covers with baffles. They replaced another set of eddy covers that were rusted and just looked nasty. The two valve covers are the exact same part number. And after a few drives, I noticed smoke or steam coming out from the breather, only when at full operating temps. I just installed new headers too and though I had a bad gasket, but its not coming from the headers, or out of the sides of the valve cover, only the breather.

I'm assuming this isn't normal, is it? It never did this with the old valve covers. And the rubber seals are brand new. Engine only has 75 miles on it since rebuild. I have a breather on the passenger valve cover and a oil cap on the driver. And I read that I should have a pcv instead of an oil cap. Pcv on one side, breather on the other. Is this true?