some of it is same b or c. but not a lot.
you could make money off side marker lights since they work for b-bodies.
some of the fender turn signals do too.
I think the remote mirrors and passenger mirrors have a pretty big demand, but they are being repro'd now so you don't get the money you used to.

c-body specific stuff like wheel lip moldings, door edge protectors and tail light surrounds are usually highly desired since most are missing or dinged up beyond repair.

when I parted mine out, I got money for the hood, trunk floor, door panels and glass as big parts. only those items listed above moved.

oh and if you have the chrome along the floor under the doors. don't remember what they are called right now for some reason.