[rocketraider]

There will be one 4x10 in the center of the dash, and one or possibly two 6x9 openings in the package tray. One of the package tray openings is actually designed for the rear defog blower.

In those years even the stereo radios used one front and one rear speaker. It was actually very effective.

Starting around 1970, 8-track equipped cars used one front for left channel and two rear for right channel.

But that was the dark ages of car stereo.