they're talking about moving the whole front of the maxima to the raer of the 1200, using the fwd gearbox/transaxle, and presumably the driveshafts (with CV joints) and suspension as well. The conventional RWD diff will be on the scrapheap, and no tailshafts or uni joints in sight.

It will need custom links to control toe, but that should be easy to knock up using part of the fwd Maxima steering linkage/ tie rod ends. I can't see any real difficulties apart from making the chassis section to make it all fit in there and provide anchorages for engine/box assembly and strut (I assume) mounts. It will be a very interesting project!