In 1967 they were not stamping VIN numbers on blocks, and the two-letter block code will be all you have to go by. If you can read the engine production number you should also be able to read the block code right below it.
The casting number at the back of the block by the distributor ending in "33" was all you needed to confirm it is a 400.
The cast date code should be within 5 weeks of the trim tag week to narrow down the search. L 14 6 is Dec 14, 1966. That would imply that your car would have to have been one of the first produced. If the body number on the trim tag is very low ... like less than 400 or so ... then it might be pretty close.
