[Rwillia4]

Quality brakes give you the ability to repeat similar brake distances over many tries. Additionally, quality brakes will give you, the driver, greater feedback/feel. Cheap brakes will not be consistent nor have a good feel.
The brake distance greatly depends on different Cobra kits, realize that the distances you mentioned were very good for ~1965. I can’t talk for other kits but the BDR brakes work very effectively.