Just to clarify things a bit, envision this:
The frame of your Bronco is the center point, with the body bolted to the top of it, and the suspension bolted to the bottom of it. With a body lift, you put spacers between the body and frame, thereby raising the body while the suspension and frame stay in the same place. This is good for giving you extra fender clearance. With a suspension lift, you are putting in taller springs which adds space between suspension and frame. This raises everything but the axles. The axles only get raised when you put the bigger tires on that you now have room for!
I just put the Superlift 4" suspension lift in my 79, which I highly recommend. I did it in my driveway, with basic hand tools, and it took me about three weeks of evenings and Saturdays. Broncograveyard.com and 4 Wheel Parts got most of my business. Good luck.