can I update my 91 LS 400 radio (tape deck) to a newer one with a cd player? i

 

Do you mean repalcing the entire unit with an after market? Yes, you can, Sound FX sells the kit for after market units as well as the harness. Only drawback is that you cannot use the sub anymore as the wire harness that is sold does not have the wires for the sub amp. Or do you mean replacing the unit with a unit that has the cd changer function? You might be able to but requires alot more than just swaping the units. Try looking in this forum and you will find that other members have tried doing this change. Some have just completely removed the stock equipment and install all after market. Good luck

Leo