I called AC-Delco today to ask if this filter had the anti-drain valve in it. I also asked if they had quit making this filter. The guy said they still make the UPF52 and the UPF44. The only place to get them though is through a GM dealer. I'm thinking of ordering another case of them even though I still have 8 left from the last case I bought. That way if they decide to discontinue them again, I'll have a good supply.
Wayne
Wayne