Sorry my response for the swap was so short in my first post. There really isn't much to add, It is just as easy as pulling the motor and dropping the 6.0 in. So my donor motor was from a 2002 Cadillac Escalade,I pulled the motor and tranny complete(accessories and wiring harness) I stripped the engine and replaces the pan gasket and valley pan gasket and oil pump pick up tube O-ring, knock sensors,rear main seal and gasket. All of the original 6.0 accessories and intake were taken off and stored away. I reused everything off of my 5.3,even the starter that people say don't work on a 6.0. But it does and with the 6.0 fly wheel. %.3 intake and fuel rails, throttle body were kept intact and reused. I did end up using the 6.0 air box and mass air flow just for the decal that had the 6.0 on it. the 5.3 and 6.0 have the same part number for the mass air flow. tranny was rebuilt and installed, It shifts amazing and firm now. As I said above in the first up date, I have no engine light no leaks and fired up on the shot. I had a little bit of lifter clatter but went away quickly.
So still on the 5.3 tune and the performance is noticeably better. It don't feel like a tank anymore, acceleration onto the high way is effort less. I am not beating on it cause it's on the 5.3 tune but is a tone better than before. Tomorrow I have an appointment to have it dyno tuned, I can't wait to see what I get after that!!! I will update again on the tune when Its done and try to post a video.
Anyone thinking about doing this swap STOP thinking it is well worth it.
any question feel free to ask.