Trying to get power out of an f series engine is always goin to be hard and frustrating and u wont get much gains. However some of the basic things u can do r exhuast, CAI, better filter, maybe extractors? u already seem to have done half of them is the prob...Otherwise the money u put into the car tryin to make it faster is prob better off saving with for a future car because u will get better power gains per dollar if its spent on a nicer engine. Hope this is some help