In the stock 99-02's there are 2 grills in the pad that are prolly for cooling the front difs, if its something else let me know. The newer trucks have a slightly different style. After looking over pics it seems some people have block offs and some dont. I have a 2wd that had the block off plates (pn 15018587) that I took off. They just pop out. Does anyone know if this negatively affects air flow (milage or et). There is another plate between the hole openings and the radiator grill so air just goes into the area behind the skid plate. Could you pull that too or would it affect the air pressure going to the engine bay through the radiator. If you have these plates yank em cuz they look like .

Just a heads up.

 

I pulled my 2 small plates off of the bumper pad a long time ago. I think it'll be better to have them off, since I have a tranny cooler and it'll flow more air to it.