2001 5.3 Yukon XL transmission swap to 4l80e?

Newb here!! I have been looking around and I have kind of go some info on it, like the 32 pin input shaft/gear for the Transfer case, and reflash of pcm, and modified crossmember, I guess my question is is there anything I need to do to mate the 5.3 engine to the 4l80e transmission? I am pretty good with fabrication and stuff, but I read that the mounting plate will match up, then I read it will need to be modded, which one is it?

The truck has 170k and I can already tell the transmission is slipping a bit, so I just want to go all out and swap it for the 4l80e. Thanks for any info/writeups/experience.

-Matt

It will bolt right up ,u will just need the 80e flexplate and spacer behind the flexplate ��

CHEVROLADE: Thank you very much, needs .575 spacer looks like. Then the PCM reflash. Seems like a lot of work. I want to go through with it though.