Hello, here's the situation - The battery cranks over well, the starter is turning, and right when the engine normally fires (2-3 seconds) there is a grinding sound like gears, so I shut it off - what can I do?

GM starters are notorious for a poor starter design that must be spaced with shims. Typically sounds like a metal clashing sound. It could be other items but id check the starter mesh._

Thank you, I'll pull the starter and take a look-

Does the noise occure while you're cranking the engine?
Or does the engine actually start up and then you hear the 'grinding?'