2004 Silverado LS6 Swap?

Hey guys i have some common questions which i sure you will be able to help me out with, and give me some advice to if you have any hands on experience with similar swaps for im planning on doing this with a fiend and myself.

1. Will the LS6 engine bolt right in place of the old 4.8?
2. Will i need the LS6 ecm or can i reprogram my 4.8 ecm w/ HP tuners?
3. What type of wire harness could i use? or where could i get one made?

My main plan is to buy the engine and new built up 4LE60 4 speed automatic, but i also wanted to know though just in case i can get the engine is if, would a 6.2L LS3 bolt into my truck? and what type of automatic transmission model would i be looking at since its a gen IV engine? Thanks!

Yes a ls6 will bolt right in place of the 4.8L

You can just get your computer reflashed i think.... and i do beleive the 6.2L will bolt up to the 4l60E.. If i'm wrong i'm sure one of the guys on here will correct me...