K-H brake swap done, but doesnt stop!

Well back in the day when I was much younger and a bit more stupid, and no disc o tech brake swap articles we used to swap front disc from various cars onto our A and B body rides (think 1980s). No master cylinder change out, or proportioning block, etc. The car's braking was improved. Was it optimized? NO! Was it improved? YES! Not sure what the OP cause is here, but the cars would stop pretty good with just a spindle and caliper installation.