2983713 is on the harness and is in the parts book.
3513427 is in the 70-71 & 72 parts books and is listed for a 71 & 72 E-Body.
Both are listed as - WIRING, Accessory Lamp, Map, Ignition Switch and Title Lamp.

One of the differences is the ignition lamp connector. I don't have a wiring diagram for the 71 or 72 cars, so I can't determine the other differences.