Tuesday Torque: IHC Slideshow From Pinckneyville...

...courtesy of Gary Bahre, the ILEngineGuy.

Lots of M's, plus a few LA's/LB's.  These are all throttle-governed, closed crankcase engines.  They are smaller and lighter than their predecessors.  The M's have grease cups for the mains.  The LA and LB engines are later, with oil splashing the main bearings.  Engines evolve!