Dang. Sorry to hear about your knock. I tossed up the idea of a 6.0 swap myself. But its really not worth it. Its more than just throwing the motor/ecm/wiring harness in. I helped a friend of mine put a heads/cam/intake 5.3 into his reg cab short bed and it was a BIT#%^. LOTS of little parts that you don't think about in the beginning. And its not a cheap swap either. Yeah you can the motors for under a grand complete drop out. But its everything else. I think in total he has around 4 grand into his. A new GM 350 long block can be had for around 1500 now a days with a warranty.
On a separate note.If anyone knows where I can get a nice full replacement front bumper(ranch hand, road amour, ect) for my truck let me know. I have a nice hand gun with ammo for trade.