12 bolt rear ID

A buddy of mine has a 12 bolt rear out of a '68-'72 A-body. It has the "O" style cover and no numbers (that I could find) on the axle tubes. There are several numbers and letters cast into the center section. They are as follows:

S94189 CFD9 170 BU

He was told by the guy he got it from that it has a 3:73 open diff in it. Can anyone give me some more info on this one? He wants $250 for it and I wouldn't mind having a 12 bolt for my '76 GMC Sprint.

Never mind....did some research and took the cover off. It's a '68-'70 Cutlass 12 bolt w/ the 10 bolt ring gear. Oh well.