Can anyone help decode Mopar distributor numbers?

Interesting, I will wait to hear back from Halifaxhops.

In the meantime I had had someone outside FABO chime in on the published application for the Mopar Electronic distributor with the part number 3656763 and they say the Mopar book lists it as for a 340...

Does anyone know if in 1972-73 the 340 engines were paired with 4bbl or 2bbl or both?