whats up guys.

Ok got a buddy with a 03 common rail 5.9 4Door short bed

he has a quad rail moddifer on it right know but knows of a predator (downloader type) and was wondering if he could stack the 2? if so great

also the truck has air aid boost tube and a 4inch exhaust. rebuilt transmission.

anyone know of any kind of little/cheap mods to do the the engine etc...

thanks