i just went though this on my 63 wagon 9inch drums, the grinding noise was actually the metal rolled edge of the shoe grinding against the drum i needed to put new hold down springs on the shoes and noise is gone i used some good used ones till i order my new pack of springs my dad said to change the springs every other time u do the brakes hope this helps,check for the metal being shiny
if it is the brakes needing to be adjusted turn the adjust at the bottom of the shoes it looks like a wheels with teeth on it adjust until they drag slightly not too much or ull get heat cracks like i did dad had to show me whats up.