We called them scatter shields--a flywheel coming apart even at low rpm will cause a lot of damage.When I used to race 1/4 mile they had. Clutch cages in case the clutch exploded.. I'm sure they have it for automatics too don't they? Be safe.
As said above, balance is critical. Some engines are internally balanced, others externally with the addition of a small weight to the flywheel or metal removal from same. This can change even in the same engine family. Was the engine in question available with a standard transmission? You could always use it direct drive to power your new drill press . Mike