They are all 2 track, but the 8 track had 4 sets of stereo L+R tracks next to each other. The tracks were so thin there was a huge amount of hiss to them. Dolby would recognize this hiss frequency and cut it on cassettes. dont know if they had Dolby on 8-tracks. I remember seeing blank 8-track tapes at Radio Shack for recording.
We had a 77 Lincoln Town car, huge boat that had an 8 track in the radio, the entire tuning scale would push in with the 8-track tape. kinda cool how they did that, and there was a little joystick for balance and fader, "Ford Quadrophonic Sound" or something like that.