I have a 91 firebird and want to put a 90 front bumper cover on it. I just like the look better. I know it can be done and what's involved, but I was wondering if there is any reason to avoid it.

 

I have a 91 firebird and want to put a 90 front bumper cover on it. I know it can be done and whats involve, but I was wondering if there are any disadvantages to the swap. I just want to make sure I'm not missing anything.

 

If you have GFX, any 85-90 bird cover won't look right.

 

I've considered that. If I decide to to the swap I would probably swap the ground effects too

 

I agree that the 85-90 looks way better than the pseudo-4th gen 91-92 noses.
As mentioned, the ground effects will not match so you will have to at least replace the front fender effects. Also if you have fog lights, they won't fit on the older bumper.
If you don't have gfx, the 2 issues are the metal bumper support and headlights. You can modify the 91-92 support, but much easier to get the one that goes with the earlier nose.
You will need new headlight assemblies and turn signals. I'm pretty sure you can use the same motors, but the whole headlight assembly will need to be swapped.
Besides needing new parts for the swap, I see no downside except for the possible loss of fog lights. I frankly hate the 91-92 front end almost as much as I hate 4th gens . Ugliest car ever!!!!!

 

Thanks! And I agree, it is really ugly!

 

I did the swap on my bird. I used a 85-90 bumper support as that was easy to get off and swap. For the headlight doors I swapped the tops and headlight buckets and bezels to the 85-90 style leaving the motors alone. I had to readjust stops etc. For the Fogs I used the 85-90 style as well as 85-90 turn signals. Some of the original wiring is short so either carefully and neatly extend it or try replacing with a 85-90 harness. I am extending mine by soldering and heat shrinking the wires.
I did not replace the whole headlight assembly but I could have.
With the ground effects you will need at least the 85-90 front fender effects pieces and drill holes for them. I replaced all my side ground effects. To do this I had to remove the metal inner support bolted to the door and fill some holes and drill new. The rear quarter ground effects also have new holes to be made. For the rear bumper because my nuts did not want to come off, the bolt was turning, I cut the plastic inner support to work with the 85-90 rear bumper. You could also just swap the plastic support with the 85-90 style. The 91 metal bumper impact bar is cut different on the ends but can be used.
There is always a chance that your 85-90 front cbumper cover may have shrunk a little from heat and cold if it has been sitting conpletely unbolted. Mine did.
I do not remember why but I also had to swap in earlier style headlight bulb connectors. I just took the right connectors and unpinned the wires from the old and repinned them into the new connetors. Very easy with just a small flat screwdriver.
I love the looks of my car with the earlier style bumper.

 

Yeah I do not like the looks of the 91 and 92's at all, just looks liek they tired to hard.

 

91phoenix, Are the front fenders on the 91 - 92 the same as 85 - 90? After reading your post I am sold on doing the swap. If anyone needs a 91 bumper cover I will be posting it for sale or trade in the classifieds. I don't know if I'll have any luck getting rid of it there as I am in the middle of nowhere (Wyoming). It would be sweet if I could find a member close that was looking to swap their 85 - 90 to a 91 -92.

 

The fenders are the same but the ground effects holes are in different places. Easy to change.

 

As Stealtht/a said the fenders are the same. The differences are that the 91 front fender ground effects were attached by double sided tape to the fender where the 85 to 90 bolt on. Just drill holes no patching there. The rocker ground effect Probably has a different hole at the rear of the front fender but I can not verify that right now. I will look when I get home. I swapped to 85-90 T/A fenders at the same time because I found a pair for $60 in Dallas when I got other parts. I still have one of the old fenders so I can check easy. I will let you know for sure. It is just one hole either way though.
Other than the ground effect mounting everything is identical from 85-90 and 91-92. All aftermarket fenders are for all models 82-92 with or without the fender vent holes.
The only thing I noticed when I did the swap is that the front center of the bumper cover sags a little at the edges from the hood by the turn signals. I will need to loosen all the center retainer bar bolts and try to align it better. Just one more thing to do.

 

I could have lived with the 91 front bumper but I had a very unique way that I would of described the rear bumper and side ground effects so I had to change them. I got the 85-90 T/A bumpers and most ground effects as spare parts when I bought the car. For me it was a no-brainer.

 

I went out to the work shop and looked at the 91 fender I pulled off and the two mounting holes for the ground effects are different. The 91 has them below the lower body crease and the 85-90 has them about 2 inches above the crease. As I said before the fenders are the same except for the ground effects holes and vent cut out.

 

Thanks for checking! I have a list of other things to do to it before I spend the money on this mod but it will definitely happen. This weekend will start the rust battle. Watch out floor pans!