What kind of boot? and what kind of crampon/binding? (heel and toe welt, heel welt only, or strap-on) Sarkens are pretty aggressive crampons, are you climbing vertical ice, or?
Most of the companies making crampons make (or at least made) a long center bar for bigger feet--you replace the center bar that came on them with the longer version to fit a bigger boot.
Rock and snow here is a very reputable dealer--if you call them they'll know what they are talking about and can help you. They carry parts from all of the makers: https://www.rockandsnow.com/45085/b...MIFvrJqXtVuPDQ5VqrI4bgm9aXgjq3URoC284QAvD_BwE