I am fixing to buy a 4l80e for my 02 gmc sierra 2wd to replace my old 4l60. I was just wondering if anyone has any install tips or should i buy something else. I cant find anything on what i might encounter doing the swap, like will i have to change my wireing harness, driveshaft, and stuff like that.

 

Check out speed Engineering, they have everything that you need to do the conversion.
It will be much easier for you as you are 2 wheel drive.