The quickest way to tell which axle your Bronco has is to look at the top of the steering knuckles where the Front End Housing is connected to the Knuckle.  On a Dana 44, you will see a large castle nut threaded onto a ball joint.  On a Dana 30, you will see a king pin cap with four bolts threaded down into the top of the knuckle.

Dana 30 Axle:

Dana 30: 1966-1971-1/2 Ford Bronco

Dana 30: 1966-1971-1/2 Ford Bronco

Dana 44 Axle:

Dana 44: 1971-1977 Ford Bronco

Dana 44: 1971-1977 Ford Bronco

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