10" Rear Brake Problem

Have a 73 Duster with 10" rear brakes that need replacing. Just found out that there isn't an auto brake adjustment cable system, just a manual star adjuster against the spring. Has anyone come across this before? I ordered a maxi-pack only to find that the springs do not match up to my factory setup. Any input would be appreciated. Not happy with manual adjustment setup and would like to go with an automatic self adjuster.