Stork C Series French Horn Mouthpiece in Silver C10

If you're playing an 8D (your flair just says Conn), the Giardinelli C10 is a really common choice to start with. Since Giardinelli doesn't exist as a manufacturer any longer, you'd need a clone. Stork makes a great one (https://www.amazon.com/Stork-French-Mouthpiece-Silver-C10/dp/B0088YRJFE/) but if you're looking to be as cheap as possible, Faxx clones are usually pretty close (https://www.amazon.com/FAXX-Giardinelli-Style-French-Mouthpiece/dp/B00F8Y0TH2/) A new mouthpiece won't fix your high range, but some mouthpiece/horn combos just don't work well. Might as well start with a known good combo for your instrument.