That's what I'm going to do. They still sell 4x10 to 6x9 adaptors. From the looks of it retrosound is the only company that makes 8ohm speakers. I also bought rear speaker panels sold by dixiemonte to mount 6.25 speakers. The old ac delco 8 am-fm 8 track I have is 4 channel 45 watts 10 0hm radio outfitted with an aux jack. Very limited with what you can do unless you pay alot for a conversion.