440 Six Pack Carburetor Question

A little follow up on this bowl.
I'm thinking it's an older bowl just by the look of it. I've had it on quite a while now, maybe since '84/'85. When I bought the six pack setup in '78 it already had a 4 bbl VS bowl on the front. I can't remember what carb that dual feed bowl came on when I swapped it.

I pulled the bowl off as I'm re-painting the intake and carbs are over due anyway. 34R64842B is the Holley engineering number from within. The fitting tap looks like factory or someone was as good as factory on a mod. Glare got me a bit but that is a " 6 " not showing up. A net search came up a goose egg.......
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Thank you for that number, Dave!