From what I've heard and seen, exhaust modifications to these trucks (i've mostly researched the 5.4) seem to yeild much better results than modified intakes do. Does this have to do with the 3 valve setup? I've heard some people say to not even bother with a aftermarket CAI.

 

Yep, its not good to get an aftermarket intake unless you get custom tunes cause it makes the truck run lean. A good setup is the gotts mod for the intake and a good SI/DO or true dual exhaust. The truck will breathe much better. Also custom tunes from php or troyer or any other good tuner can get you some more hp.

 

I plan on doing a full l/t header back dual exhaust setup once my warranty ends. I'm thinking through intake modifications. I'm considering putting vents in the side of my fender to route cold air to my intake and the passenger side into the engine bay just for added cooling and ventilation. Is there anything I can do to the throttle body, like modify the walls or the butterfly. I know modifying the butterflies on some carburetors can reduce turbulence in the flow into the manifold.

 

and I will be getting custom tunes for performance and one for feul mileage

 

The factory intake is already routed into the fender, so it is basically a cold air intake. The only problem is the inlet hole is small, and the gotts mod gives you more flow. The gotts mod with lt headers and true duals and custom tunes should give you some good performance gains.

 

I know every behicle is different in every environment. but any guess on what kind of gains?

 

I would think about 40-50 hp on a performance tune with the an intake modification and headers with true duals.

 

thanks. that's a lot of help