G'day Max and twostroker
For me, the Briggs Type Number is proprietary and rightly so.
I think it goes to confidentiality between Briggs and their clients.
Think of it as customisation or a deviation from the standard type.
The irony is that 'the standard type' could vary from market
to market and from time-to-time. How is that so ...?
When I worked for Briggs I had a good glimpse at
Briggs' Engine Application Centre at Milwaukee.
There, customers would send their machines [mowers, tillers,
snow-blowers, log-splitters ... etc.] to be tested for best match
between engine and machine.
Sometimes, when a known Type could not be matched an
additional type number was required.
This could involve anything considered minor to the Model Series -
gov springs, jetting, PTO dimensions, cooling, etc
Briggs does publish type number identifiers in their parts books;
they just don't link any information that would link a specific client
to a specific type.
In other words, there is no 'decoding' to be done.
Random changes - based on client needs - produce the
next type number.
I think that's right from my memory of Briggs.
Cheers
-------------------
Jack