if your leaking sc oil from under the snout, chances are they used the old gasket or worse, im willing to bet your leaking oil from the bolt that goes straight down into the lim from the snout. my gasket broke when i did my coupler, and i just loaded the bolt threads with rtv and it sealed it up.
but being that your going to take it off a new gasket should fix you all up. vac leak and fluid leak wise.