Soft brakes after rear disc install

This seems to be a common theme on rear disc conversions. Especially putting together a non component matching brake setup.
There is really no reason to replace the rear drum brakes. The front do the majority of the stopping. Need more stopping power ? Use more aggressive rotors, pads and even dual/sided piston calipers.
The brakes are the most important safety system on your car, especially for driving on the street.
The main reason that most modern cars come with 4 wheel disc is more for economic reasons than safety.
At the factory/assembly line, disc brakes are cheaper and require no adjustments on installation.
Most have ABS pumps to give high line pressures and electronics to constantly adjust individual wheel braking .
Not so on our older cars.
It would take thousands of dollars to duplicate the brake systems for the old cars.
But most everyone tries to go the economy route mixing parts from different manufacturers and than wonder why there are problems.
Try mixing in Ford or GM parts when building a Mopar transmission or engine and see what happens.
Stick to rear drum and your problems will go away and your car will stop great again, or just upgrade component quality.