Hard (power) brake pedal

Did you put on a new Master Cylinder? Proper one for Drum Drum, or Disc Drum. Power or Manual Master Cylinder ?

If you have Drum Drum the master cylinder reservoirs should be the same size.

What is the Bore of your master cylinder ? 15/16", 1", 1 1/16 ??? the larger the bore the harder the pedal will be as you have less leverage and less of a stroke making it harder to press.

Did you add Front Disc Brakes, that is a whole other can of worms.

More Info Needed . . .