Info needed on rear end code

[Sklptrljay]

Just spoke to a guy selling a complete rearend. It's supposed to be a posi 3.73 from a 72 or possibly a 71. I asked for the code and he gave me this #; KBU WO16 IF.
I looked, but couldn't find this code on any links I had saved from this site. He was an older gentleman and maybe his eyes deceived him, I know they can be hard to read sometimes.
It's a one and a half hour drive to his place, so I would like to have the info if possible before I go see it.
Thanks guys.