Have you guys ever heard of this before?

[D1 guy]

I talked to jwt today about getting my car tuned and they asked me what kind of injectors was I wanting to use. I told them the nismo 555cc injectors. Their next question was...."are they the yellow topped 555cc injectors" I said yes. The guy that I spoke with told me that he had some good news for me. The yellow top 555cc injectors (or what nismo calls 555s) are actually around 615cc injectors. He said that their are 2 different kinds of nismo 555cc injectors and the yellow top ones are actually 615cc they are just called 555cc injectors by nismo. This sounds strange but I guess that jwt knows what their talking about. Have any of you guys heard of this?