Carter AVS 4615S -vs- 4615SA

[arcticmopar]

What is the difference between these two?

From what I see visually is the 4615S has one idle mixture adjusting screw, and the 4615SA has two closer to the base where the 4615S has this area capped off. Difference or Purpose?? The 69 Plymouth Service Manual only references and shows pics of the 4615S model.

Also, where would I find a rebuild kit for the AVS 4615S or 4615SA?

 

[1968 man]

Send it to the guy that done mine $ 250 bucks and shipping was ?35 bucks.

 

[69bfan]

The "A" references the part number to be a service replacement piece as purchased or supplied as an over the counter direct replacement part.