Brake cable cables come in two different styles. One has a mushroom shaped end the other has a barrel shaped end. Some generic cable sets have one of each and you cut off the one that you don't need. A mid 80s road bike might need either.

Shifter cables come in two styles too. There's Campy and there's everything else. The Campy ends are just a skosh smaller.

Plan on having to cut off the extra length. I use a cable specific cutter for that job because the end doesn't fray as badly. I prefer to buy my cables over the internet and buy "slick galvanized" cables. Slick cables are drawn through a die so they're smoother and galvanized steel cables are easily soldered. I solder where I plan to cut the cable and cut through the solder. If you do a neat solder job it will never fray and can even be drawn back through the cable housing and replaced.