You could eliminate the front differential, cut the splines off the ends of the axles and bolt them to the wheel bearing. They are what keep the wheel bearings preload on 4x4s. The 47re will bolt up to the LA bellhousing, but you'll need a controller to make it work. As for the mounts, I'm not sure what the difference is, but there have been a ton of these swaps in Dakotas and other trucks.
Great info, thanks! I can fab my own mounts and brackets when needed. I was going to go with the 727 i picked up, i think the 4x4 transmission is completely different than a regular 2wd transmission, but not totally sure.