[Verne_Frantz]

Hylton, Tonawanda didn't step up to the cost of a deck grinding machine like for the small blocks. They used a circular cutter, or grinder for all the W motors. Also, it's very common to see the assembly date stamp with the first suffix letter in a gang holder, then the second suffix letter was added by hand. That same gang holder could be used all day on all standard trans motors, then the second letter made it more specific to horsepower, carb, and cam. It's not that uncommon to see the second letter struck more than once, or bounced.
Verne