Yes, with a but. I'm not an expert on the 5R55E specifically, but, in most automatic transmissions, you have to change the output shaft to convert from 2wd to 4wd versions. In most cases, the output shaft is the last thing to come out when tearing down and the first to go back in when re-assembling. This means that you basically end up rebuilding the transmission to convert from 2wd to 4wd. If your goal is to avoid the expense/time/hassle of a rebuild, it's probably not worth it. If your goal is to have a spare transmission on hand, then it will be up to you whether it is worth it or not.
