Does anyone know if it is normal for a 2 1/2 Y pipe to have these dimensions?

2 inch down piping and 2 1/2 back from the welds?? I am just a little confused and want to figure out if I got F***ed. I thought it was supposed to be 2 1/2 all the way back???

 

Hmmm, shoun't be like that since they don't advertise it like that. Might just be they make um all wrong though. Thats mass production for ya.