Moving the pivot point on the brake pedal
Just had this issue with mine 4 wheel disk crazy hard peddle and it took a lot of effort in pulling it up and got sketchy a few times when some one jumps in front of you than is on the brakes so I ended up getting a few remote boosters done as I needed access up top for rocker adjustments, these are mounted under the front guards up front , night and day difference with min foot pressure in pulling up. I’m running the 15/16 master , Kelsey hays fronts and a ford rear . I had my hubs made to except the large bolt pattern but keep the small ball joint factory rotors.my vacuum is on the minimum side 12 inches but they work well.