[AKBroncoII]

I'm looking for a lift for my 77 F150 and found a new Rancho lift for $200 and thought that it was a good deal. The only problem is that it is for a 78-79 Bronco/F150. What is the difference between that lift and the one for the 77? The only thing I could think of is the rear block. I wasn't sure though. Maybe someone could clear this up for me.

 

[AKBroncoII]

If no one can answer this question then what's the difference in rear suspensions between the 77 F150 and the 78-79 Bronco/F150