Like I said above, with an Android phone, get the Torque pro application (~5$) and use a Bluetooth adapter with your OBD2 port on your truck. It will ask you to make a profile of your vehicle (fuel capacity, weight, engine size, ect.) and makes calculations based upon that. Then, in the "real time data" section of the app, there are options to have fuel % remaining, range, mileage and a host of other cool things.
However, the fuel level % is NOT calculated from the fuel level sensor in our trucks (not sure about 0411 pcm's, but the stock one on my 98 doesn't). You have to manually tell the program how much fuel you have in your tank, and it calculates the remaining fuel by subtracting the fuel YOU say is in the tank against how much fuel the truck is burning at the time, only as the sensors on the truck poll it.
I"m not sure if this app is available for other phones/operating systems (apple, blackberry, windows) and have heard that the ELM 127 adapter quality can be questionable when buying online, so please do so at your own risk! Sorry for the late reply!
Link to the ELM adapter that I have:
http://www.ebay.com/itm/Auto-ELM327...251?pt=LH_DefaultDomain_0&hash=item4855da1a4b
