I have talked with Modern Driveline (Idaho) about doing this in a full size (78-79) and they are developing a kit. (No timeline given)
WH's has a display with this trans and adapter on their sales floor, but it is so new that no one can answer any questions about it. (Back in early December).
Silver sport Transmissions (East Coast) was the originator of the kit that Jay Leno used in his GT500 Bronco at SEMA. At the time they had an exclusive on selling it from Tremec. The owner recently sold the company and I guess that opened up the opportunity for other Elite Dealers to sell the product.
So I can't answer your questions, but would suggest that you check in with WH's to see if they have any new info on the swap and/or the same for SST, since they did a lot of the development in the begining.