I know that corner/bumper lamps are all different from 88/89 to 90/91, even changing within 3dr/4dr/crx.

Are the headlights all the same?

My 90 Sedan has a crack in one lamp and a moisture in the other so I'm just gonna get both headlamps replaced, but nobody specifies which model, just listed as 88-91 Civic.

 

I'm pretty sure they are all the same... including the 88-91 crx. I believe the sir headlights are a little bigger but still compatible.

 

Sir headlights will not work without the Sir front end. But to answer your question yes all 88-91 civics and crx's have the same headlights, i believe the headlight brackets are different between 88-89 and 90-91 though, but you can use your brackets on the new headlights.