Hold on.
There is a 997GT3 Cup. They MUST make a 997GT3, for homologation purposes, and i suppose the street GT3 can't have a different engine than the race GT3 (again, homologation rules).
I don't think they're racing a wet-sump engine, so i say it's pretty safe to assume that the GT3 (street) will have a dry-sump one. Maybe a drysump variant of the one on the Carrera S?