I know that this topic has been brought up before, and I'm probably beating dead horse, but I cannot find any "closure" on the topic. Has anyone figured out what tames or lessens the lifter knock, whether it be oil type or thickness, oil additives, fuel, other internal engine additives (sea foam, etc). From what I've read, it's not really bad that the lifters knock, and it doesn't help to replace them because they will do it again eventually. Just really curious.