All ihc-manufactued sv (v8) engines have an identifaction stamp on a pad machined into the block. The pad is located on the passenger side of the block, at the forward corner right below the cylinder head interface.
The number will include the engine displacement, along with the designation suffix for series (such as "a" or "e" if applicable. And it will also carry the unique serial number for the oem engine assembly.
This pad May be easily seen with a flashlight and possible an inspection mirror underneath the exhaust manifold on the passenger side.
This is a 345 block that has just come out of bake and blast at the machine shop. It's sitting upside down of course on the dolley. Look in the lower left hand corner of the block pic and you will see the pad along with a number stamped on this one.
Any engine block that has a number string cast into it is simply either apart number for the bare block before machining or some sort of identification for tracking the mold/die/fixture/tooling that was involved with manufacturing the part in order to be able to qa and correct and manufacturing defect discovered down the line.
