I have had my 04 Lariat 4X4 for alittle bit over a month now.
And I was wondering what bolt-ons I could do to it for better
gas mileage and Towing? Would a Diablosport chip or tuner
work on these? thanks

 

Tuners can help if you're not standing on the gas all the time like me. Also a bed cover can help 1 to 2 MPG. Just my 2 cents.

 

There doesn't seem to be a whole lot out there to help on mileage. But lot's of things for power. There are a couple of kits out there for cold air induction, like Air Force One and AirRaid. There are some split cat back exhausts you can bolt on like Borla and Flowmaster. Troyer Performance offers custom reprogramming that yields some good power. At the moment there's not a whole lot more. A lot of the companies are still developing their products due to the complete overhaul of the F-150 and 5.4L.