I like a lot of the members here prefer to buy my oil and filters in bulk, especially when the items I need are on sale. I have a few ACDELCO PF 61 filters that I got at a really good price a couple of years ago. opened them up the other day only to find that couple of them have some rust forming. it is showing up outside the media, threads and antidranback valve. located in the seam that goes around the top of face. it is surface rust. looked inside the filters and they look the way they should .would you use these or just scrap them ? not sure if trying to clean the rust off would be a good idea, if any particles would end up in the holes of the drainback valve. I could cover all of the holes them with tape and use steel wool lightly to remove the rust. the outside of the filter is perfect. what say you ?