Cadillac CTS-V - V Rear replacement!?

Does anyone know the date when Cadillac started updating the rear's to either the 04-05 STS rear or the 06-07 CTS rear? There is an 05 V for sale that had the rear replaced 10/17/2004! What are the chance that the replacement was the stock differential and not the STS rear, or the soon to be 06-07 rears.

they didn't use the sts rear, they would have replaced that one in 2004 with the same model that they took out. the upgraded ones didn't come around until the '06 model year, then changed slightly again for the replacements that went in in 2008 and currently.

In other words, that '05 still has an '05 diff.

Late 05 they started to swap to the 06' IRON diff!

Thanks guys.

Late 05 they started to swap to the 06' IRON diff!
Nope, it's aluminuminum..inum.

Anyone have a link to read about the specific details of the rear end?

cadillacfaq.com might have some stuff.