Hey guys, I was looking at summitracing.com today and found a underdrive pulley kit for my truck (Silverado with a 4.8L) I was wondering what you guys thought about them. Pro and Cons

 

The UD Pullies will give you an additional 3-5hp plus 2-3mpg. The most important of the pullies are the Crank and Alternator. The AC pully is not available for all models. I suggest that if you plan on running any heavy radio upgrades, you upgrade to a 105 amp Alternator. Otherwise, you will see a small increase in HP, but the mpg is what matters.
Hope that helps
Greek