Putting two speakers in the dash, when it was only built for one

I've been contemplating making kick panel speaker pods for my '66 Dart - right now it has just rear speakers, and I don't like the way it sounds. I don't doubt that the stock speaker could be improved on even if you keep the same location, but you can get a better stereo effect with kick panel speakers. On the other hand, I'm going to have to find out how the new engine buildup ends up sounding - it may drown out any stereo that doesn't add an unacceptable level of dead weight. :)