Points ignition wiring question

The terms condenser and capacitor mean exactly the same thing. Condenser is the original name. The name "Capacitor" arrived later.

If it's mounted on the coil bracket (I've seen many on Mopars) it is the radio supressor and should be hooked up on the positive side of the coil not the side going to the dist. By doing so it smoothes out the voltage ripple thus reducing radio interference. You mentioned you didn't notice a whine. The ignition system dosen't usually cause a whine in the radio. That comes from the alternator. Ignition system interference is usually in the form of static.

Condensors/capacitors have a few different uses. Just as GotDart said they are also used to make points last longer. In this case they are used as a surge supressor.

BTW You probably know this and just made a typo but the cubic inch of your Dart is 273 not 267