Does anyone know what a HH2978A8 distributor came out of?

Thanks

Got picture? Brand?

Got picture? Brand?

Stock GM points type with the little door in the cap.

Stock GM points type with the little door in the cap.

There are more numbers on it somewhere, the older cast iron had a metal band tag on housing neck. The newer have the part number id stamped on the housing side. Most all early GM had these point well windows, seem to have started somewhere in mid 60's or so.