That's not as a horrible grinding as you may think! You need to pull the covers to confirm!
I just went through this year. Sounds can trick you a bit. When in the driver seat it sounded to the right, I was ultimately very wrong. I also perceived a bad scraping noises.
It was the driver side and one PR pushed trough the #1 exhaust rocker and one missing PR to #1 intake! It Sounds very familiar to my issue!
I was very Fortunate and the missing PR was easily retrieved from the valley.
Cost me 2 rockers, one intake and one exhaust and a set of PR's + cover gaskets! Could have been much worse!
Also a new shorter bolt to replace the one longer of three short rocker bolts!
The first above #1 was bottomed and not at all confidant the rocker was flush to the pads!
Don't panic yet! I believe the Bolt above the end at #1 rocker was too long and was having some high RPM flex there!
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