DC remembered (very kindly) my specific need for a v-belt, but might have forgot I sprung extra $$ to switch to a full serp belt set-up so now my 320a has a v-belt pulley on it hahaha. Would that even work?
Have them send you the right pulley. You should be able to swap out fairly simple - if not have a local shop swap the pulley for you...instead of waiting for shipping twice again.