I'd agree on OEM to a point except ACDelco is junk, most using fibre end caps. Even though the ACD seems OK for my LM2 Duramax with metal end caps, I use Wix because it uses a silicone anti-drainback valve, which is better for the cold weather here. However, I've seen some of the ACD with metal caps come apart with the glue not holding the caps in place.