Replacing your stock MAF (mass air flow sensor) with an aftermarket MAF will give your truck some extra ponies to get down the road. These sensors are very easy to install. Just unplug your stock MAF and remove it from the intake system and replace it with the new MAF. In 15 minutes your truck will have more HP. The way this works is by increasing the size of the whole in the center of the MAF and altering the electronic reading of your sensors. These readings alter your fuel curve and other settings for max performance. These aftermarket MAF's run about $300 to $400. 
If you do not want to spend $350 on a mod that will only give you 10 to 15 HP there is another free way to do almost the same thing. You can modify your stock MAF to give you a noticeable gain. What you will need to do is remove the screen that covers the inlet side of the MAF. This screen serves a couple of tasks. It protects the sensor coils in the middle of the MAF and alters the air movement. Removing the screen will allow more air into the MAF and cause the sensor to give different readings to the computer. The result will be a noticeable gain in HP. 

To remove the screen you must first remove the MAF from the truck. After removing the MAF you will see the screen that we will be removing. Place the MAF on a table screen side down. With a flat head screwdriver and a small hammer hit around the inside edges of the screen. Be careful not to touch the coils in the center of the MAF. After you have made it all the around the MAF turn the MAF over screen side up and pull the screen out of the whole. If you are not able to remove the screen turn the sensor over and hit the screen again. Once the screen is removed place the MAF back into your intake system. The screen can be saved for other projects. After the removal we could tell a difference in HP. Not bad for free.