Nope. Wiring harnesses are basically considered 'Chassis' harnesses, and the 'Engine' harness is totally separate. Get an EZ or Painless harness for everything in the truck, and use a stock LS harness that you will need to mildly modify. There is a lot of info on
www.lt1swap.com for the necessary modifications to the LS harness to make it an easy enough hook up.