What I did was I changed the fuel injectors for an old engine that I took out when I replaced my 5.2L with a 1996 5.9L. I would recommend trying to get your hands on different fuel injectors because messing with the wires may mess you up in the long run.
2001 5.2L take out-swapped fuel injectors instead of wiring harness (easier)
1996 5.9L install-sanded and painted with no new exterior parts, just new gaskets with fuel injectors from the 2001 engine
Any other question about this swap please feel free to ask me.