You could run a Dana 300 with an adapter off the back, it's a small tcase and get a remote shifter for it. If you get the modules and switches for the tcase it shouldn't be too hard to wire up. I don't have a diagram for it but the Astro van guys do it with S10 cases alot when they want 4wd instead of awd. As for the 5L30E, you'd need to have the computer completely reprogrammed and probably some harness modifications to make it work, and since no one really modifies our computers (JET doesn't count, they just make air/fuel adjustments, I don't think they can rewrite the whole ecu) I don't think it'd work.