Hi everyone, I'm new here but I wanted to share what I did to the stock amp on my 87. I like to keep my radios stock but I wanted to make the audio better. The stock amp's 30 year old capacitors were probably pretty dried up. I desoldered all of electrolytic ones and replaced them. Cost me less than $14 dollars from digikey. It definitely sounds a lot better.
Make sure you are confident in your solder skills before attempting. Thanks.