I have a 70 and I think the person I bought it from put in an 8 track AM/FM radio but it is not hooked up. I'll try to list all the wires I remember: Coming from the back of the radio itself is a gray and gray/red stripe, gray and gray/blue stripe, single black, and single yellow. Then coming from somewhere else is 2 light green, and 2 black. Then I think there is a harness with more wires coming from it, one of which is a red that had a clip that connected to the yellow coming from the radio. When I connected those 2, the 8 track that was in the player started playing, but there was no sound. There was also a double black wire off by itself, which I think is the antenna, but it could be anything. So if anyone can help me in anyway, I would really appreciate it. Thanks alot.

Well, the gray & gray/other color are probably the right and left speaker wires. If they're not hooked up to speakers, that would explain not hearing anything. You probably identified the power wire by hooking the yellow up to red (which was probably a hot wire from the fuse block). The black with the yellow may be ground, and you probably also get ground through the chassis. The antenna wire is usually a coax (thick black with a center and outer conductor) which needs to connect to a similar cable coming from your antenna (if you have one). There might be a wire to control a power antenna too, which you don't need. Sorry for all the "probably's" in this, but without seeing it...

You might try going to an auto audio installer and buy a "pigtail" for an early GM installation. They usually come with a generic wiring diagram.