I'm surprised it doesn't come with some sort of posi from the factory. I've had a zexel-torsen which is same type as the eaton tru-track and I like it a lot. I also have the g80 locked from gm the eaton gov-lock which seems to work okay. Honestly I think they all work pretty good provided you drive right even a locker. A locker like the detroit is supposed to unlock when turning and lock when you need. They have a reputation of putting people sideways but i think you are okay if you just drive like a sane person should. We welded my buddy's diff to essensially a full spool and he drove that thing daily wheels chirping on every turn. There is nothing to lock manualy on any of them like an old 4x4. The 2x4 lockers are self contained mechanisms that just work automatically.