Extra radios, lotsa ice and drinks, impact gun, spare front and rear tire, nitrogen tank for the jacks, duct tape, obviously all necessary fuel (figure out which jugs / spouts pour the fastest unless you are required to do 2 10 minute stops, etc)
We brought all this and more to the 8 hours that we did - but that was with 3 drivers, a 1996 RT/10 and that went through a whole lot more consummables that you will in a CC for that length of time.