Just updating this thread. I'm an idiot.
The white clip in the beginning DOES fit I was just installing it wrong.
What I found was 83-87 got the metal clip. Around 88-89 got a small black clip, and the 89-93 cars got the white clip in the original post. The white and black clips interchange and the repro shops just sell the white one for the 88-93 cars. No idea if the early cars can get the plastic clip
All three will install in my '88 once I figured out how. I believe the slots for the metal clip disappeared in 1990 with a sheet metal change for that part of the body
I replaced the incorrect metal clip I installed with the correct plastic one for my year i purchased NOS.
White one is a tad wider, but that's the only difference.
For the sake of completeness, in case someone searches, this is the 79-82 prop rod clip