the Trans ecu's in the two cars talk to the Cars main ecu. so i dont think going from auto 4wd to auto 2wd would work.
going to Manual 2wd on the other hand, should be no problem. as long as the car can be tuned(emanage f-con etc) you should be fine!
but you also have to keep in mind that the 350z is a lighter car, so some of the feel maybe in that.