I need a little assistance. One of my U-joints gave out today

(thank God for a shroud). I pulled the top half of the shroud to check out the damage and look for a part number. Much to my surprise, there is not one number on EITHER of my u-joints. I got a 81 Elim. Day-cruiser w/454 and a berk jet. Can anyone help me out? Maybe give me an idea or a part number?