I went to the junkyard today becasue they had 2 Caprices there and I needed a bumper shock. I was going to pull a headliner out of the Caprice, but it looked different.

The Delta has a clip for holding the sunvisors in place (in the center) however the Caprice did not, and the dome light is different (no big deal) Also the rear headliner was a little lower than the front. My Delta's did not do that.

They also had a 1979 Seville sitting there. It has the center piece, but it also has handles above the rear doors (I will not be putting them in my Delta) I looked at the VIN and it is a "B" body. However I know that the B Body line had a slight change in 1980.

The Seville is a 4 door so pulling the headliner would be a bitch, however the car has NO seats in it, so that would make it easier to pull out.

Would it fit? I have no headliner in the car and the only way to get it home is to install it right on the street. I had to do that today with a new back deck I bought out of that Caprice, with a third brake light. Just gotta drill for that now

 

It won't fit.
1976-79 Seville is not a B-body car, it's a K-body. The K-body was based on a stretched X-body chassis (Nova, Omega, etc). Early Sevilles shared little with any other GM car, contributing to their high price point when new.