fuel pump\brake,tail lights,back up lights,wiring for everything from the cab back

Attached are all wiring diagrams. Just to be safe though, note the color of the fuel level sensor and the fuel pump and lights before you start cutting wires. If you plan to completely remove wires, there is a lot of insulation and electrical tape to undo. So, you might dis-connect everything and remove the wires you don't want. One problem you might run into is that your warning light on the dash may come on if the PCM looks for a signal that is no longer there. Some things tied into the PCM are not what you would logically think should be involved with the PCM. Just a word of warning to make sure that you don't take out any PCM wires so double check or leave anything you have doubts about.