Curry 1 BBC vs Kelly 3C
The Curry 1 BBC has a wider cup diameter.
Cup Diameter
The Curry 1 BBC has a cup diameter of 17.27 mm / 0.6800 in compared to 17.02 mm / 0.6701 in on the Kelly 3C — a difference of 0.25 mm / 0.0099 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a very deep cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
Throat diameters are essentially identical at 4.06 mm / 0.1600 in, so resistance feel will be comparable.
Material
The Curry 1 BBC is described as unspecified, and the Kelly 3C as Lexan polycarbonate. Material affects mass, warmth, and how quickly the piece responds.
Which is better?
Neither mouthpiece clearly dominates the other — the right choice depends on your embouchure, playing style, and the sound you're after. Try both if possible.