It will go by the original fare class not upgraded. Depending g on how AS sends it across to DL you may have to call DL to get credit. Sometimes DL systems only get the U flown with no original fare class and thus credit zero miles. A phone call to DL if that happens is normally all it takes. They can get the ticket pulled up and see the original fare class and credit. I've done it before and it seems random as if it works or if I have to call.