More traction can gained by changing your stock differential and/or gear sizes. Most of the trucks that are bought off the lot do not have a locking differential and have higher highway gears. True this setup is great on the highway but on a drag strip this will hurt your times. Also this factory setup does not give you the traction that you need in rain a snow. If you have the chance to order your truck or luck up and find one you can get your truck with a locking differential and lower gears. If not you can have lower gears and/or a locking differential installed. This is not a project that can be done by everyone in their backyard. The gears and differential needs to be installed and adjusted properly. If the gear sizes have been changed your speedometer will show the wrong speed. This can be corrected with an aftermarket computer program or you can have your dealership correct your computer. Different size tires can also cause your speedometer to be wrong and can be corrected the same way. If you do not know what size gears you have or if you have locking differential there is a way to know. If the truck has the factory rear-end, GM has codes that it puts into its trucks that you can see what you have. In the glove box there is a white sticker that has a bunch of 3 digit codes. The codes that start with the letter "G" deals with your rear-end. You can cross reference those codes for the answers

Chevy Gear Codes
This codes are on the sticker in your glove box
G80 = Locking rear differential
2.73 = GU2
3.08 = GU4
3.42 = GU6
3.73 = GT4, GQ1
4.10 = GT5

If you have a lot of modifications and/or you can smaller tires you might have a problem with wheel-hop when the tires spin. When talking off the rear end will twist and cause your leaf spring to bow into a s shape. The energy in the leaf releases and pops your rear-end back into place. This can happen many times and can/will hurt your drive-train. This can be solved by installing traction bars. These bars bolt onto the bottom of the rear-end and connects to the front part of the leaf springs. As the rear end tries to twist the force is redirected to the front of the leafs where they will not bow. This also helps traction because the bars tries to pull the rear-end down to the ground. Under a hard take off the tires will hook better because of the extra downward force on the tires.