I know this may be a "well it's sorta obvious question" however I feel it may need to be asked.
I am still in High School as a sophomore so I'm not really an Expert, especially when it comes to mouthpieces. I was in the market for a Dennis wick mouthpiece because the professionals some use it more than others and can produce a better quality than the others. I know it's about what is specific to you, because believe me when I was a trumpet when mouthpieces got smaller the tone got worse I was a good sound to the 7C. I became a baritone by technicality (or by instrument build (3 valve non comp.)) and I felt that a particular mouthpiece was absolutely the best for it. When I went to the same mouthpiece in the euphonium (schilke has versions in small and large shank) the tone quality worsened. I have been researching and found the SM series from dennis wick. I found one which had a gold plating on it which generally for me makes me press less which produces a better tone (I had a gold plated mouthpiece on the trumpet). The issue really is, that is says 'Baritone' instead of 'Euphonium' which leads me to believe it is a small or medium shank. I have been using a King Model 2280SP Euphonium - Legend, Soloist 4-Valve, Silver-Plated euphonium. Which I believe is a Large shank about 44mm.
The question in short is, Is this Amazon listing or any SM series in large shank?
https://www.amazon.com/Gold-Denis-Ba...dp/B00EDONO02/