tillotson carb number meanings

[Mr X]

so im wondering what the numbers on a tillotson carb have. i know that hl hr and so on is the size but what do the rest of the numbers mean? is there any way to find out the size of the bore or anything from the numbers?

specifically hl276

knowing what these numbers mean would make it alot easier to find a carb without measuring the bore.

 

[Ibanez616]

From what i understand, there is no meaning, simply a model number. The letter after the number (ex: 357a) Indicates the fuel circuitry pattern.