Ho ho ho!!
have I got a deal for the 8-track lover wanna-be!!! I have to dig around in my attic, but somewhere I have an 8-track recorder! I never used it for perhaps 15 years, but it worked back then. (As a kid, I recorded the original Star Wars soundtrack onto 8-track.) Just think, you could make 8-tracks of current CD's! (of course, it would be analog quality after all).
I'll dig in my attic this weekend, and if Radio Shack has a blank tape, I'll try it out. If it works, I'll post it. Lemme know if you may be interested. Otherwise, I'm sure someone else here may want to buy it. I haven't thought of a price yet, but it would not be more than $25, including shipping)
Not sure if this will help. My first vette was a 79. The previous owner had installed an after market AM/FM cassette in it. I didn't like it so I went to the local junk yard and found I believe it was a 1981 Delta 88 that had the original am/fm stero still in it . Fit perfect right down to the connector. If you strike out it might be worth a try, my guess is most GM cars from that era shared a lot of parts