Serial number and CPL numbers are located on a tin plate on the outside edge of the timing cover, at the front right when looking at the engine, just ahead of the injection pump or the high pressure fuel pump on common rail equipped engines.
Legend:
HMRO - High mount turbo with exhaust venting to rear of engine (mounted on top of manifolds higher than valve covers)
LMRO - Low mount turbo with exhaust venting to rear of engine (mounted alongside engine tucked under manifold almost)
HMFO - High mount turbo with exhaust venting to front of engine (mounted on top of manifolds higher than valve covers)
LMFO - Low mount turbo with exhaust venting to front of engine (mounted alongside engine tucked under manifold almost)
JWAC - Jacket water aftercooled