Gadjit, I know the feeling. I've been chasing a knock for some time and can't seem to find it. I've got a FAST EZ EFI system I've been wanting to put on, but I want to get the knock figured out before I do so I don't mask problems. I've never heard the spark plug trick, I'll have to give it a try. I like you have a fairly loud motor so not sure if how it will work on 7 cylinders. Problem with mine is that the knock is not consistent, sometimes its there on start up, and sometimes its just a small tick. Then once the car warms up it goes away or lessens...the other problems is I'm not much of an engine mechanic....I can put them together, but can't diagnose them well. I hope you don't have to pull it.