Ok, I just installed this mod, and I'm having some problems with it. First when I plug in my Ipod the FM doesn't shut off. This is not a big problem as I found I can just change to a non existent station FM/AM and drown the slight static out with music. The big problem is that the music sounds good, but you can barely hear the voices. It doesn't matter if the treble is up or down, same problem. It's not a problem with the Ipod, I checked it with my head phones. I think it might be a problem with the jack, but the only wires that it has is Right, Left and Ground.
This is on a 87 Brat