I do a lot of hauling and only have a 5.4l in my 2003 f250. Would it be worth it to put one of these in it if I'm wanting more power. Does it change that much?

Edge Evolution Programmer for Ford Triton V8 4.6L and 5.4L Edge Performance Chip EP15051

 

You would be better off contacting Mike at 5-star - he sponsors the V10 and 6.2L forums, but I think he does custom tunes for the 5.4 as well, using SCT hardware.

If you want a readout system for your truck, I believe SCT has one of those as well.

The thing with Mike is that he has spent a lot of time coming up with custom tunes for the engine and trannies in the Superduty, not just a vanilla "4.6 and 5.4" engine tune that doesn't take into account the weight and other characteristics of the truck.