You (and/or your mechanic) must confirm that ALL of the ventilation system is free and clear. The oil separator (aka "breather box") and the small vacumn line from the flame trap housing to the intake manifold are potential problems, as is the small brass fitting in the manifold (where the vac hose attaches).

Give your car several days to "drip dry." The oil probably coated everything inside the bellhousing.

Also, if you had a plugged flame trap (what your mechanic is incorrectly calling the "pcv valve" -- there is NO valve), then the front seals may be weeping. And check the big plug in the back of the head. Excess pressure can force it out, and then you have a HELL of a leak! (BTDT in my '86.) Fortunately, it's easy to check and easy to secure in place with a simple retaining strap ($0). See pix below.

Quite frankly, a dealer who does not replace the famous (infamous) flame trap on a routine basis is providing shoddy, sloppy service. You might not want them to touch your car.