www.car-part.comJust checked. search for a 96 4runner rear axle. It will bring up all the compatable vehicles and years. Make sure to call to verify the listing is correct. Check if the locking solenoid is included. they sell them separately sometimes.
$500 for a complete 4runner rear axle, 6 cyl center, electric locker. That's how I got both my lockers. I'm sure one without the locker would be even cheaper. It put up with a week of moab on 39s. Why waste money on a 4 cyl when your gonna want the 6 cyl later.