Grumpy,
I think you have a little misunderstanding on how the date code is read in reference to the above chart. This is just my opinion but I can be wrong.
The above chart is for shipping manifests and doesn't correlate to the date code. If it did we here in the States would need a much broader chart as I have customer engine with last digits that are no where on the list. I haven't seen a chart anywhere that correlate the date code with a particular plant; this is an internal item that Briggs hasn't released publicly. It would be nice if they did release it. Now if they are starting to use true serial numbers then they might include those style numbers above but I haven't seen any to date here in my shop.
Here is some examples of date codes that I have on file here as I use them to track a customer engine for service warranty.
080312YG, 0106287ZE, 070301ZA, 090327YD, 93062952, 95033132.
