All JDM honda motors stop at the last letter. (b16a, b18c, b18b, b20b, ect...). USDM motors end with a number (b16a2, b18c1, b18b1, ect...). That goes for all honda motors, not just b-series. It gets a little different when talking about UK motors though, like the b18c6 (UK type-R and stuff like that).