Pictured from left to right are the roof locator parts for 84-96 Corvettes.  

 They are found mounted to the underside front of the roof on the frame itself.

1. The cone on the left was issued on 84 to early 85's and is known as the first design roof frame.

2. The middle plate is found on late 85 to 88's and is known as second design roof frame.

3. The far right plate comes on 89 to 96 roofs and is known as third design roof frame.