They are not actually supposed to be the same, but they should not burn up that quickly.
6V points usually have larger contact area. Six volt ignition systems actually use a bit more current through the points than 12 volt systems do, resistor or not.
Nowadays you probably can't choose your variety, with the consolidation of part numbering that goes on.
Try a differant condensor. You can tell if yours is bad by looking at the pitting on the points. If there is a big pit on one side and a bump on the other, you need a better one. The optimum value of condensor will keep the point metal from migrating across the arc that forms when the points break, and keeps the wear of the contacts to a minimum. Sometimes you have to select from a batch of condensors to get one that is the perfect value to match your particular coil, and if you find one you should keep it until it goes bad.
I have to deal with this problem a lot with my motorcycle. The bike is a 4 cylinder with two sets of points and a 8500 rpm redline. Some of the newer brands of points suck and bounce at lower RPMS, or wear quickly. I buy NOS points when I can find them and they last 3x as long.
