Some of us can read    I think the biggest difference in gear ratios will be 1st and 2nd.  I think you may be able to swap out the rear section of the tranny, but you'd be miles ahead to just source a 4wd tranny.

yeah we can all read. I was just trying to help him out with the easiest and cheaper option. Didn't mean to ruffle your feathers. But yeah your right, it'd be easy (if you wanted to stay taco) to get a 4wd w59, and then the gear drive adapter then the older duals. But if your not starting out with the 4wd tranny, then in my opinion it's better to just go w56 and skip the extra adapter.