Your transmission does not have an over drive selection so the postings about turning it off are concerning the pre 2006 engine and transmission update.
The engine, transmission and cruise control computers are programmed for the best fuel economy. For most of us we're OK with the programming. If you want to change it you need to reprogram the shift points. 5 Star Tuning, Banks or other such 'tuners' that change the shift points to do what you're asking. There are some programmers that you can working directly with you to develop custom shift points. Off hand what I think you want is the down shift to the next lower gear, fourth, rather than skipping to third as it does.
The V10 has a unique power curve and pretty much comes alive over 3500 RPM. I would first consider sound and heat proofing the dog house then consider a reprogram. Also not sure about how reprogramming will effect the Ford warranty so do a bit of research on that first.