[Kurt S]

Different engine codes for the same engine / different car line were due to engine component differences resulting in a different engine assembly.
The L48 in a big car had center dump exhaust, in a Camaro they were log style. Hence different assemblies and different codes.
Nova and Camaro were the same platform and shared most if not all engine and axle codes.

Be curious what the Tonawanda records say for the L89 totals.