replacement blocks

[Jeff H]

Let me ask this question about engines. If the engine plant says it assembled x engines coded "CTB" and Chevrolet says they built y cars that had that engine code, what would Chevrolet do with the x-y engines that were left over? They would already be assembled and stamped sitting around waiting to go into a vehicle. Would they first use those as warranty replacements or start immediately with CE replacement blocks? I would imagine that the leftover complete engines would be sold as "crate" motors since they were fully assembled vs warranty replacement especially if the engine being replaced only needed the short block. These "crate" motors would explain motors with no VIN on them.