I'm looking to replace the single dash mounted speaker but I want to get the right one the first time. I've seen universal 8 ohm speakers for older cars, the newer aftermarket stuff all seems to be 4 ohms. My car is a 79, not antique but not modern-era either so I'm not sure which one I'll need and there's a 40-50 dollar price difference (per speaker, 8 vs 4 ohm) so a mistake would be expensive. I'm not an audiophile, obviously... the mono setup would be unacceptable. But I would like to be able to use the radio without the obnoxious blown speaker racket. The head unit is the factory am/fm with green digital display, LED I suppose. It works fine... I have no plans to replace it.