I have a 04 silverado 5.3 Reg. cab, an I have a few small bolt-ons but now I am looking for some more HP for better speed an racing(1/4 mile races). Now I know NOS might not be good on a engine but I want to know wich one will give me the most speed an HP for racing? A whipple supercharger or a 50-100 shot of NOS? An I know what the prices are an Im not worried about that, all I want to know is which one will put out the most speed?