The shield had been hitting on the exhausts manifold for a long time. It started by me looking at the starter shield. Some say take it off but I think that's a bad idea heat wise.
So what i found is I needed to pull the manifold to get to the full starter shield. Interesting I found the shield has 3 bolts but it goes way further up past the starter and is just flopping around at the top. I saw a perfect hole up their so I made a bracket that goes in that hole and holds the top of the shield with a couple of bolts. Sorry no pic on that.
While their I did the old fixer trick LFS lol Look for stuff so I took to looking at the shield of the exhaust manifold and it had been hitting rubbing for some time. i clearance it so no change of hitting. looking at the other side I saw no problems.
Now when I get knock its real and confirmed by using race gas. Its so nice to have a knock sensor I can trust now
Hope this helps some of you!