since you mentioned "160" film, I'm assuming color neg.
Tell the lab to push the film 1.5(or if possible, 1 2/3 stops) in development.
Your shadows won't have super duper detail, since they're underexposed, but modern films are generally fine with some underexposure(within reason).
DON'T RUN IT (NORMAL). You'll have muddy film with bad shadow separations(at least IME). Push it 1.5-1 2/3 stops