Grant my '91 K2500 has a 14-bolt semi-float with G80 with I assume is the Gov-Loc and I believe is a 9.5 inch. That's the truck you saw in Graham and is basically a driver/trailer puller. Its 17 years old, but being post '72 its not Stovebolt discussion material and I call it a modern truck.

My '89 K3500 has a Dana 70-HD with no Gov-Loc or similar ability. Until it was wrecked last year it pulled my trailer and did a much better job than the 2500.

Those two rears are not what this thread is about.

My 14-bolt full-floater I assume is 10.5 and no Gov-Loc near as I can tell. It came to me under a '50 1-ton Chevy, but is definitely not the original rear from that truck.

Then I have the Dana 70-HD I was considering for this project. I still haven't looked up the BOM number to figure what it came from... I picked it up out of a guy's yard. He said it was from a 70's or 80's GM Diesel Dually.

I also have a late 70's P30 under a motorhome and I haven't crawled under it to determine whether its a Dana or a 14-bolt. I probably should.

1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble...