The gov-lok is made by Eaton. It isn't really like any other posi or locker. It is technically capable of locking both wheels together but only after lots of wheelspin and even then often with catastrophic failure of the diff. The 14 bolt one seems to be pretty strong but its not a locker.
There is no posi available for the full floating 14 bolt.
If you want a detroit, you will need to find an open carrier first. Otherwise your only options are an ARB or a spool.