Im really kind of lost as to what i need and what i dont need for my swap. I bought a 2001 5.3 out of a wrecked 1500 truck and it came with the fuse box pcm and all of the wiring. My question is is there a tcm on a 4l80e or will the pcm control the tranny
(i know that the 1500 trucks have 4l60s)

 

Before around 2005, just the PCM would control the trans - 4L60E or 4L80E.
IIRC, TCMs came out somewhere around 2004/2006.

However, to swap from a 4L60E setup to a 4L80E requires changes to the harness and PCM. These detailed threads explain all:

https://ls1tech.com/forums/automatic...-required.html

https://ls1tech.com/forums/automatic...l80e-swap.html

 

Thanks a bunch