Put a post in the parts wanted section for 550 carbs, shouldn't take long to get you sorted. You have a couple of problems with the 750 carbs, for one, on a stock 550 engine they are two big and two, using pods will make it just about impossible to set them up correctly. Not knowing how long its been since the bike has run doesn't help either, it may need a full carb rebuild and tune up with valve adjustment.
Not enough information yet ....