"1954 drum brakes did not have automatic adjusters, so you can expect to readjust the brakes every 1000 miles or so."
You can update to automatic adjusters. Just pirate the adjusters from any 11"x2" drum brake GMC vehicle. For example, 1962 or 63 and up (without disk), chevy truck, front or back. The adjusters fit your brakes with no modifications.