I've got a '99 f-150 with the 4.6. ya, ya, I know that this engine is pretty much crappy but it's there, and i'm not paying to put the 5.4 in. SO, it has dual exhaust, k&n cold air intake,and a throttle body spacer already. Any other suggestions? Does anyone know if you can chip these or get a tuner for more power? any suggestions besides "scrap the 4.6 and put in a better motor" would be appreciated. thanks