Pretty much any car as you can modify the plastic part that goes between the door and mirror. I put one on my '76 cutlass in high school, it even added the remote adjuster.
The bolt pattern between the two studs is the same, more or less on all GM so theoretically you can bolt them on to anything with out to much trouble. Whether they will look right is another question.
I agree. List it as G-body only and you'll keep yourself out of trouble. Make sure you mention that they wont fit the 86-88 MC and ElCamino. Those cars used the Camaro style mirrors.