Hello- Does anyone here know what size the Dana is in the rear of a 2005 GTO? I am trying to order my Detroit locker and no one seems to know the rearend size. Thanks!  

The only company that makes a differential for 04-06 GTOs to my knowledge is KAAZ. It's an Australian company, and it's quite expensive. FYI, I believe the GTO rear is made by Getrag or Borg-Warner not Dana.  

Actually they are made by BTR which is a Division of BTR Indeng (Industrial Engineering)which bought out Borg Warner quite some years ago in Australia and yes Kaaz is a popular supplier,the dimensions were still the same until they went to left hand threads for the crown wheel bolts but i do believe that Eaton are doing centres as well  

Dana axles....only  

I don't think you'll find a bolt-in Detroit Locker for the GTO.  I have a 2006 and ended up with a Kaaz.  The Kaaz is very firm and locks well.  It keeps my tires to locked just pulling out of the driveway.  However, you can get a nice Ford 9" center section and you would be doing well.  It is very strong and has all kinds of differentials available.  All the way from a spool to a Detroit Locker.  Harrop, an Australian firm markets them.  

Thats good to know GTO.