I got a '99 f150 w/ a 5.4 liter, 4x4 lariate. i have dual Flowmaster exhaust, a K & N air intake, and a throtle body spacer. im wondering what i can bolt on to increase my hp. im looking at gibson headers, a Jet chip and new plugs and wires. how much more hp might i get from these add ons? what else could i get to increase my hp?

 

I have seen the supercharger from a Lightning on Ebay before. Went for about $400.