I would pull your injectors and send them to a shop and have them rebuilt. Why just change the cups and O rings with 125K on them. Many have fixed this problem with just replacing the O rings as well. The way I look at it, they aren't the easiest buggers to get to, especially pass side, so why not have them rebuilt by a quality shop? Most injector shops will have rebuilt sets sitting on the shelf, send them your cores and they will send you rebuilt units so there is little down time.
NCH
NCH