Steve T

I don't know if this is the right forum to post this in so sorry if it's not in advance.

I just picked up the book " how to swap GM ls engines into almost anything.
Chapter 6 wiring harnesses and wiring...
It has a guide for 1997-1998 engines (provided by ls1tech) and1999-2002 engines (also provided by ls1tech)
However it also says in the first paragraph of pg.73 that the vortec harnesses are still yet different from the other two. First question, what about all the other engines, and second question, what about the trucks?
Am I missing something here?

I tried searching for " truck harnesses" but didn't come up with any such guide like the ones in the book.
Any help here would be greatly appreciated.
Thanks, Steve T