Maybe around 300 hp. Without HCI the charger will not be ably to give you its full potential, The engine is basically a air pump, the more you get in and out the more power you have, the stock 5.0 is pretty restrictive in the intake and heads, You will see much greater hp level once you complete a head and intake swap, as well as the small bolt on parts to go with it, ie injectors throttle body headers ect.