I used kens auto in Stasburg ND, and picked up a late 2007 6.0 LY6 (VVT) with a 6L90E, the wiring harness, ECM, exhaust y-pipe, and MAF from the same 2007 GMC 3500 SLE HD, with 4000 miles on it. All that for $2500.00, shipped to my shop in Northern IL. Mark, at Kens, said all they do is get in 5 truckloads, of vehicles, a week and part them out.
http://www.kensauto.com/