I am swapping 85-90 Ground Effects onto my 1992 Firebird. I have the bumper cover, but I don't have the brace and the honeycomb behind it. In the junk yard there is a 89 base model without ground effects.

So, the question is, is the honeycomb from a non-ground effect car the same as the ground effects car for 85-90 Firebirds. As I understand the metal brace is the same between the two, so I'll just grab the whole assembly.

I searched and most of the threads ended up with people trying to dissuade people from putting ground effects on their Formulas instead of answering the questions. To keep this thead from going this way, it's a 92 Convertible with ground effects already, but of course both the front fender ground effects are trashed and I vastly prefer the 85-90 style but finding an 85-90 Convertible Firebird is difficult and I prefer the 90-92 interior.

 

Metal bar and crash pads are the same.
There is a pair of plastic support blocks below the metal bumper. The ground effects bumper cover uses longer ones. That's the only part that needs to be changed I think. There is also a plastic belly pan under the gfx bumper cover to direct air to the radiator that the non gfx nose doesn't have, but most are missing in junkyards.