Sadly, the engine code didn't appear in the VIN until 72, that's why more 67 427s have been judged by the NCRS than Chevy ever built

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As for a VIN starting with FLA, that's a mystery to me. It should be 194378S4XXXXX. The only letter that would have ever appeared in a 68 VIN is "S" for St. Louis. Where is this number stamped, is it the full VIN on the A-pillar or are you looking at the block or some other VIN derivative? If it's the engine block, 3 digit codes didn't start until '70 and all of the Vette blocks through 79 (I think) started with a "C".
Unless I'm just missing something, this seems a little wierd to me.