So my Bronco, like many came with 4 drums and no brake booster. Many people upgrade to discs, but before doing that I would suggest adding the booster and seeing how it feels. Although drums can be a pain to tune in they have a ton of stopping power if properly bled and tuned.
I used a kit from Toms Bronco Parts to install my Power Brake Booster/Master Cylinder (cheaper kit from amazon that I cannot vouch for). I also had spent some time rebuilding all four drums prior to installing the new booster.
New Brake Booster Installed:
Old brake master cylinder:
The installation is very straight forward. There was no modification that I had to make and it bolted right up. Some people report issues with going into reverse when you have a 3-on-the-tree style manual shifter. I noticed it at first, but it was only a slight rub. Once installed you do have to bleed all the brakes. Make sure you adjust the drums correctly!!! You have not have noticed a slight pull to one side with a normal brake master cylinder, but with the new booster you defiantly will, which could be dangerous if not tuned correctly (thing massive pull on braking).
Toms Bronco Parts has a great write-up with pictures on this project which you can read here and I can't speak highly enough of their support on order/projects.
So far my brake booster has been holding up great and no issues in time its been on there. The master cylinder will rust however, so I suggest spraying it with WD-40 or similar if that matters to you.