I would think you would be better off with a Junk Yard or an Insurance Total vehicle. Reason being is that you will need the new ECM and more than likely a new 6spd. auto to match up. Could probably match up a 4L60E but not sure. Your best bet would be to check out the performancetrucks.net forum and poke around to see who has done the swap and what it needed...$$$ time etc.
Rob