I want to switch a 1991 firebird front bumper with the previous years trans am bumper, is this possible?

 

You have to change the support bar and headlight assemblies as well. I did it on my 87. If you don't have a parts car it can be expensive.

 

Without ground effects, direct swap with the reinforcement bar

Headlights are the same, not sure where he got that from, only diff is the size of the light itself. Everything else is the same

With ground effects, Youll need to swap all the 91-92 style for the 85-90 style to look right. That includes the rear bumper cover

May I ask why your ditching the aerodynamic nose for the old blunted one?

 

i always liked the older nose, the 91-92 just looks weird to me

 

The upper half of the headlight pod and the headlight doors are different. The plugs for the headlight are also different. The doors are aesthetically different only. The drivers side has the words PONTIAC made into them. The trim around the lights and the lower airdam parts are also different.