Look at the shape of the front cover. Even if the front cover matches the Dana 44 image below, you still need to make sure it's Early Bronco width. That would be approximately 58" wide at the wheel mounting surfaces on the rotors.
You can also look at the knuckle as shown in the second photo. However, there is a pretty rare hybrid axle that doesn't follow this. The front cover and taking a measurement is more accurate.