rear end question?

assuming from your post, the "center chunk" drops out the front of the axle housing and the back of the housing does not have a cover plate, It is more than likely a Mopar 8 3/4. Take the wheels and brake drums off, remove the nuts holding the brake backing plates to the end of the axle tubes, ans slide the axle shafts out about 6 ". Then you can remove the bolts holding the chunk in and it comes out the front. (driveshaft has to be disconnected of course)