i have a 06 5.4L lariat ext. cab 4x4.. im looking into some mods and i started reading about new pulleys..i was just needing some suggestions on a good set and a rough idea how much hp pulleys will get me. and also cold air intakes i hear nothing but good about the k&n 77 series and i just found the slp performance f21000 which is kinda unique looking. but im looking for hp!also theres the airforce1 but i dunno it just seems cheap.