[Torrey72]

Starter needs to be shimmed to give specific clearance between starter and Ring gear. A paperclip will give you the correct gap between teeth/gears. Just get under the rig and engage the starter gear by hand and use the a straightened out paper clip to gap the teeth at the place they mesh.
The starter will make the most damaging sounding noise and hang up if not set up correctly, and will destroy the meshing teeth.
Shims may need to be used across both mounting bolts or just one depending on clearance required, one side shimmed will increase clearance and other bolt will decrease clearance purely a case of trial and error to get it right but providing the paperclip clearance is met you will have a sweet sounding starter. Check clearance in three different places on flywheel by rotating it.