of the 30+ years i have ran wix filters, i have had several where the threads were bad. i have a 3/4-16 "form" tap which, as the name suggests, "roll forms" the threads with no metal removal. those i have fixed easily, and i have a plated 3/4-16 bolt i use to check the threads on every filter i use because i fill each filter before installation. the only other defect i have come across using these filters is once in a while, for whatever reason, the filter comes without a gasket. those, i return. the 51515 fits my whole fleet, including my FWD minivan with the 3.3 engine, so i buy these by the case.