90 r2500 suburban 454, flex plate or bearings?
if the two sound the same, whats the easiest way to tell which one is causing the high pitch scraping? no knocking, just a vibration and scrape. oil pressure is good
When did it start? Did the sound come all of a sudden or gradually? Did you
make any changes right before you heard the noise?
I'm not sure that the flex plate would start scraping out of the blue. Can you safely be under the truck while it is running? If so try to isolate the sound from underneath.