What motor is this 327 or 350

[PxTx]

I'd be suspicious that GM would replace a small journal block with a medium journal CE motor. It would be more likely that a 65/66 knowledgable Corvette owner may have made the choice for himself outside of warrany.

I can tell you the block we used checked out way above average on thickness and other critical areas. I say it is one of the best stock block foundations. Good luck!