2004 Chevy Silverado tune up

i have tried to perform a tune up. on my truck, it has a 4.8 v8 and i have replaced plugs, wires, air filter and i can not find the fuel filter. the hanes manuel states that 2005 has not fuel filter but as you can see i have a 2004. i have checked by the frame rail from the gas tank to the fire wall. is there a fuel filter? and what else do i need for a tune up?

thanks