New computer, wiring harness, motor & trans. If the if the existing wiring harness' (excluding engine harness) truck are compatible with the 4.7 pcm then that would make things easy, but if they aren't then you are in for a wiring nightmare.
Not sure of the accessory layout, but you may need to change the a/c lines and powersteering lines. The fuel feed line might need to be modified as well.
There's probably more, but that's a start.