Why ship a block to Michigan when you have a foundry? This seems a little suspect to my little bit of knowledge
We have researched this issue on 60's Corvettes, where there is evidence that a small number of 3858180 327 blocks were cast at Tonawanda and machined/assembled at Flint; had nothing to do with any production interruption or problem at the Saginaw Foundry - it was simply a continuing machinability audit to ensure that Tonawanda-cast blocks were totally interchangeable with Flint blocks through the Flint Machining and Assembly Departments. They're easy to spot, as they have the usual earmarks of a Tonawanda casting, but the pad machine code stamp starts with an "F" ('66 and earlier) or a "V" ('67 and later).