You can always velcro the Scangauge onto the steering column like I did on my Sierra, and the Scangauge is much more than a set of gauges. It allows you to monitor stuff that the dash gauges don't display. For example, I often watch the O2 sensor output so I can confirm when the engine is in DFCO.
Just a note from personal experience. I had done headers on my 5.9 to replace the ugly log style manifolds and it helped quite a bit as far as MPG goes. I'd watch after the intake, my brute force apparently does let cooler air get to the engine and it hasn't helped my mileage at all, in fact, it is worse.
If you don't put on the metal heat shield you might do better though.
I'll make sure to use the scanguage before and after to know if the brute force is worth keeping.
I just flushed the system and put some fuel addative from Lucas to clean out the injectors. Got worse FE for that tank but since then I've been averaging about 12.5 mpg which is up 2.5 mpg, pre cleaning.