Power brakes were an option. There are a lot of after market companies selling power brake booters for our 60s trucks. The differences are the newer boosters are dual masters and have the proportioning valve. They don't have the OEM bracket that goes between the firewall and booster. The bracket angles the booster towards the fender for more clearence. You may not need the bracket, some of the after market booster have a smaller diameter. There is a bracket in the for sale forum.
Larry
