On the 5.4L V8 F150 (mine is a 2002) - cylinders are numbered as so:
Passenger side: 1(closest to front bumper), 2, 3, 4(closest to cab)
Drivers side: 5(closest to front bumper), 6, 7, 8(closest to cab)
Firing order is 1-3-7-2-6-5-4-8
P.S. yes, i know this can be found elsewhere.