pin/harness change 5.3 to 6.0 tahoe/6l80e?
 

Do i need to do anything to run a LY6 where the 5.3 was in a Tahoe with a 6l80e?

Long block only swap is ready to drive to tuner or will the trans need more work?

What year Tahoe, and what year LY6?

2012 Tahoe with flex fuel 5.3 and 6L80e.

The LY6 and L92's I have looked at vary in year but have pretty much the same price- I can get an L92 from a 2012 Sierra with the 6l80e if that will help.

Would a certain year vehicle LY6 or L92 make this a drop in swap?

All Gen IV engines ('07-'14) interchange nuts and bolts wise. Get the ECM that comes with any engine you get. Everything should be plug and play then.