Guys, I want to install the 85-90 fender vents on my 91 firebird, but before making a hole in the fender, I need some help.

Please look at the pictures.

On the red vents you can see clearly a section at the bottom (circled in yellow) which has a different paint from the rest. I guess that this section will go under the ground effect that you can see in the other picture (circled in red). Now if we put this section of the vent under the ground effect, it could be that this will make thickness and it will remain space between the ground effect and the fender.

If there is someone that has ever installed these vents, please give me some help.

Thanks to everyone will help me.
Alex.

 

if you're going to install those on a 91 firebird with gfx, you wont have that problem you're describing. The 91 gfx arent as tall as the older ones, so no overlapping will occur. You're best bet is to get 82-84 vents. They are the same size dimensionally, but the hole doesnt stop an inch or two short from the bottom. Heres the best pic I could find of mine. This is older, but you can see the mounting holes on the fender where 85-90 gfx would go. The vents sit completely above the gfx.

 

Mitch,
thanks a lot ... now I understand ...