CW Cobra: I agree with "01Lightning". I have my boost gauge mounted to a custom made "Pod" on my driver's side front sill.
The only thing needed is to "T" tap a suitable vacuum line that is as close to the manifold as possible. Since I was already replacing my "Spaghetti-Tubing"; I arranged for a brass, "T" tap; off of the tube leading away from the manifold (98, Romeo, 4.6Ltr.). On my engine that feed is on the manifold, right below the T-Body,on the L-side of the engine.
I used high temp. emission hose for the part of the run that is over the engine. Then I extended the vacuum line up to my front piller (funny I forget how to spell that).by going down the wheel well, and up the weather stripping until I reach the mounting pod.
I provided a pass way for the vacuum tube by drilling a suitable hole at the bottom of the cable channel which runs under the doorway. I did use a water-proof bulk head penetration to clamp the hose, and prevent moisture,water entrance.
You can tap into the IP Lighting Circuit for power to operate the internal light of the gauge. I don't know what color that circuit is in a F-150, but in an Expy. it is Lt.Blue/red. If it is not the same in a F-150; check the lamp in the ash tray for the appropriate color pair. Maybe you can even tap the power from there.
Have a nice weekend.
"98X"