4 ohm vs 8 ohm

IIRC, (I am assuming that you are talking about 1970ish +/-), the speakers were 8 ohm with the factory radios. You do not want to use the 4 ohm on it's own as it is hard on the output transistors. Just like revving an engine with no load. You need an 8 ohm sinlge, or two 4 ohm in series.

@moparmat2000 made and supplied a nice little speaker frame that fits the original dash bolt pattern, only it holds two 3 inch speakers.....A nice piece.