I pulled my small block down with a few thousand miles on it a couple of years ago and the chain was thrashed. I had forgotten to put a drilled bolt into the normal spot, I also didn't put a slinger on there but I didn't normally run one anyways. So when I went back together with it I drilled the bolt, put the drip thing on, and used a slinger to cover all of the bases. I ran it several more years and another several thousand miles and a good amount of racing. When I changed cams the chain was in the best shape it had ever been in during a teardown. So I will buy into at least one of those making a difference.