i have them and i like them. when i only had exhaust, intake and programmer with stock 3.42 gears this is the mod that pushed me over the top as far as being able to spin the tires. albeit, not for very long or nothing spectacular but you could tell there was a power gain.

price wise, they are way overpriced. wait for a used set but don't count them out. remember, every 1 hp adds up..

 

10 hp seems significant. I have an oversized alt (145) and dont run any huge stereo yet. What about water pump?

 

The HP gains aren't nessasaraly where its at. Its less spinning mass and your motor can rev easier.