I bought a 2008 GMC Sierra (TX Edition) truck about 6 months ago. It has the 4.8 V8 in it. I want to do some baisc upgrades to get more HP. Suggestions? I have looked at the following:

1) Cold Air Intakes (there are a lot out there)
2) Cold Air Intakes (Supercharger System) basicly an intake with a power fan
3) Spark Plugs
4) Performance Chips
5) Thortte Body Spacers

What is the best Bang for the Buck??

 

For air intakes Brute is a great choice, and JET for performance chips.