So I ended up buying a 91 formula the other day and for some reason they put an 88 front end on it. Well I found the correct 91 front bumper cover but I was wondering if he headlights are the same between the 89 and the 91 or if I need to switch those out too. I'm trying to put the car back to stock. What is the difference between the two? I would like to buy the minimum that I need to.

 

They do have different P/Ns,82-90 have the same,91-92 are different.

 

The 91 and 92 headlights were a tad smaller than previous years.
the black plastic housing on the 91 and 92 doesn't have the top lip that aligned with the turn signals when the lights were down. 91 and 92 also had "Pontiac" embossed on the driver's light top panel.

Since the inside actually holds 2 different size headlighs, it may be different... but check, may be able to swap parts out...

 

The housings are different with the only part that is the same is the door, if I am remembering correctly. I have them both. It's easier to just swap them out, it is only 4 screws holding them to the body.

You're going to need more than just the bumper cover to make it all work if they changed the front end properly. The bumper, and the cover brace are also different between the years.

 

I paid for a set from a member on here but haven't heard from him in 10 days. So I don't know if I want to buy another set yet. As far as the bumper cover, I replaced he front support with the correct one including the absorber. I already put a 91 front cover on it to test for it, but it is a gta cover with ground effects and my car is without them. So I'm looking for a plain firebird front cover for the 91-92.