A new pipe is not going to give you more speed. The reason being is that your engine can only reach a certain number of RPMs. A pipe may make it go a little higher, but not enough to make a huge difference in speed.. If you want a good pipe, check out the Ritter pipe. It gives you a lot more torque, and a bit more higher end.

About the only way to get more speed out of your truck is to change the gearing. This will make your acceleration slower, but give you a little be higher top speed. I am not sure what gearing you would want to go with, maybe someone else can answer that one.

Why are you wanting to make your truck go faster? Is 40mph not fast enough? Just asking is all .......