I'm not sure about the adapter for an AW4, but it will definitely be too long for a standard wheel base YJ. Just lifting a YJ causes issues with driveline angles. Adding a second TC, even if it only adds 6" to the drive line length, would not be possible on a standard YJ. It would require the significant lengthening of the wheel base to get acceptable drive line angles. I'm not saying it's impossible, I know that it has been accomplished. You're just looking at some major modifications. Here's a link to a thread that describes the modifications with a Chevy SB and a TH350.
Offroad design 203/205 doubler - Pirate4x4.Com Bulletin Board