Greetings . . .

Google has a book about Rochester Carburetors online:
Google Books: Rochester Carburetors by Doug Roe
pages 116 and 117 show how to decode jet part numbers. I believe that the 'B' series and '2G' series use the same 'approach angle' so the jets should be interchangeable.

Charlie Price has got 2g jets:
Vintage Speed

regards,
stock49

[Linked Image from 49fastback.com]