Eventually the flywheel stopped in exact same position and truck wouldn't start.
MDS pulled starter and noticed bendix gear was damaged. We looked into the flywheel housing and saw the flywheel had teeth chipped and that was why the starter couldn't grab.
MDS replaced the starter, flywheel with stock and the flexplate was upgraded to a BD Duramax Flexplate.
Check out their website for the specs and benefits of this minimal upgrade: