Yea my friend has a 04 silverado Reg. cab with a 5.3. He has the Hypetech programer but he wants to try another brand like Nelson. But he needs some more info on them. Does anyone know a web site he can look at to find more info an does anyone know some prices that it will cost him? He's also looking ino getting a Whipple Super charger any one know some info on that to. He wants to get his truck to at least break into the 12's on the 1/4 mile. So if you know some other mods please let me know.