I have an 83 Z28. My rear spoiler doesn't line up correctly. The short piece on the left rear fender and the long piece on the hatch glass is lines up nicely; however, on the passenger side there is about 1/2" misalignment between the long hatch piece and the right rear fender short piece. It appears that the long piece on the hatch glass needs to be moved up toward the upper hinges on the passenger side. I have seen a few early 3rd Gen with this misalignment. Someone told me that the holes in the hatch glass are not in the right location and this is forcing the metal piece at the bottom of the glass to be out of alignment and thereby affecting the spoiler piece too. Any suggestions or information would be appreciated. Thank you.

 

There's a tech article on how to fix this problem properly.
https://www.thirdgen.org/hatchalign

 

Pictures? I just fixed my hatch, and the hatch was unaligned due to the trim on the glass. (pain in the butt to remove sealent in there)

 

Thank you Joe Tag for directing me to that hatchalign link. I appreciate it.

Gary.