12 bolt differential info needed
 

So I am rebuilding the rearend for my 65 which has the 64 style panhard bar and 17 spline axles.I had a 12bolt gov loc laying around and decided to use it and save some money. I bought new 30 spline axles and a 3.73 thick gear set to go on the carrier that had the ring from a 2.76 ratio on it. Being that the carrier was a gov loc I assumed it was a 12 bolt truck 3 series unit. Until I had bearings and gear mounted and dropped it into housing. The ring gear bolts hit part of the housing and even with all shims on one side backlash can be measured with a tape measure. So I removed from housing and set it next to the original. After some internet research I found dimensions for car and truck 12 bolt carriers according to the series. I have determined that this is a car series 2 carrier. Has anybody ever seen a gov loc in a car or did they ever build vans or trucks with a car housing?

Re: 12 bolt differential info needed
 

The made a few versions of that thing and it could be from a 10 bolt.
Jimmy

Re: 12 bolt differential info needed
 

After searching the web I decided to call a know it all of differentials. The guys at Randy's Ring and Pinion had an answer. Although rare and there is no aftermarket support for it apparently there is a GM 12 bolt Truck series 2 carrier. The only ratio was a 2.73.