How many, have nursed a knocking Rod home?

I worked with a guy years ago at a small service station. He had a Chevelle station wagon with a 307 in it. We could hear that thing knockin about 1/4 mile away from the shop....I kid you not. He worked with us about a year. Drove that car every single day. It knocked LOUD I am hear to tell you. He babied the heck out of it everywhere he went and as long as he worked there it never let go. I remember him doing an oil change on it there and all kinda metal came out, lol, but it kept right on runnin.