The stock air box that came on our trucks has a little hole in the front of it that it pulls air through. The more air you can get into the engine, the more horsepower you will recieve. So, to increase air flow through the air filter and on into the throttle body, cut the air box open to recieve more air. This is a simple and free mod to do.
You want to cut the corner walls of the box out that faces away from the engine. DO NOT CUT THE WALL that faces the engine. By doing that, you will be sucking in hot air from the block. Cold air increases the engines power. Then intall it back just like it came.
Once done cutting, just put it back the way it came. You will hear the difference when you step on the gas pedal!
In the driver front side of the engine compartment is where the air box is. Its easy to take off the top. Just four screws and its up.
Then pull the cover back and the air box is below. pull it out. You can see it here with the air filter still on. Notice the tiny hole that air is supposed to come through.
Here is the inside of the box.
Now here is the modification that i did with my jig saw.
