I have a 4l60e and stock converter that i pulled out of my 99 RCSB 4x4. I swapped to a 4l80e. It wouldn't shift into third correctly almost felt like it was slipping heavily. Trans has 170k on it. Very good trans to start rebuilding for a mild project. I had to move it outside this weekend to make room for something else in the garage. It is wrapped up in plastic on a pallet and
covered in a tarp in the bed of the truck. $200 OBO for trans and converter just to start the ball rolling. Pick up is preferred. I can get pics if needed and you can inspect it if your local.