Read the carter information here in carbking's website:

http://www.thecarburetorshop.com/Carburetor_ID.htm

I don't see anything there that answers your question. Sounds like engineering changes would be denoted with a letter after the "S." As in 2100S__. Carbking knows best and might reply here eventually.

I've got a 2101s I will take a look at to see if I can find a similar number.


1951 3100