Zblad

I bought a used 2009 legacy gt transmission and rear end. I checked the transmission code when I picked it up and It was the right one but couldn’t check the rear end. Long story short I got home and pulled the rear end cover off and it has DS37:9 ha 723 engraved into it. If I do the math the ratio is 4.11 but shouldn’t it be 3.9? Basically is this the wrong rear end?