If you're in Houston there could be a pull-a-part around you that may have one. Especially if it is for a truck. Might be worth a look on their inventory lists to see what kinds of cars are sitting around in those places.
Trucks use the big bearing and also a different bolt pattern, plus you you have to get it shortened. Pretty tall order but you might get lucky if somebody's parting out a big block Torino, Montego or maybe a 71-73 Mustang / Cougar and if their willing to sell one axle.