I pulled my turbo to replace it with the ct20b and I noticed that my head gasket is leaking oil from the side and back toward the driver side compartment. I know oil leaks from head gasket is rare but unfortunately it is the case. I also noticed that my motor oil becomes milky only after 500 miles, so it could be coolant leaking into the oil system. Anyways I wondering should I go with a metal head gasket or the stocker? I heard that the stocker seals better if the head is not machined perfectly, which gives it a bit more tolerance.