[1993Suburban]

Got the truck to start up today without too many issues. Put it up on blocks and crawled under. The flywheel teeth looks like they have been grinded in certain areas. And I don't mean the height-th of the tooth. It has about a centimeter or two ground off on the side of the flywheel facing the engine. It doesn't look like to me it is enough to keep the engine from starting, as long as the clearances are what they should be. What could be causing it to grind like that? The spots look "fresh". Maybe I am holding the starter too long after the engine starts causing it to grind? Haven't got a good look at the starter gear itself yet. Will need to pull the starter out to do that. Have been driving it around today with no problems. Once its warmed up it will start right back up with the flick of the key. Maybe I was holding the starter too long figuring it wouldn't start before.....