I read this post on the general discussion board and replied. They are very different mouthpieces. The S-80 is a bad match to a vintage Conn horn. It's square chambered design will effect your intonation. The Vandoren Java mouthpiece might be a better piece, but they have a high baffle and a fairly small chamber also. I would check the intonation with the Vandoren mouthpiece and see if it's acceptable. Use an electronic tuner, and play from hi C down to low Bb, and notice the difference in pitch between notes and octaves. Some fluctuation is normal. Intonation isn't perfect on ANY horn. You have to make the horn play in tune. But, if there is a big difference, with some notes playing sharp and some notes playing flat, and the sax seems impossible to tune, then your mouthpiece isn't matching up to your horn. For a Conn transitional horn, I'd recommend one of these three mouthpieces: Otto Link Tone Edge. They cost about $70.00, and are pretty easy to find. Giardinelli has the best prices I've found on Otto Link Mouthpieces. Ralph Morgan vintage, or excalibur mouthpiece. They are available through www.junkdude.com. They are a little more expensive. A vintage alto piece will run $99.95, and the Excalibur is priced at $260.00. Meyer G Series or Richie Cole mouthpiece. These are large chambered mouthpieces that will work well with your horn. They are also pretty easy to find. Price is around $85.00 for the G, and $105.00 for the Richie Cole model.