This is sitting under a 66 C-10 that my buddy is looking at. I have never seen one but figured if anyone has, he's on here.
Either out of a Ford big truck from around 1939 to the 50's, or some Studebakers had the same unit. Full floater axles. Show us pics of the brake backing plates and we can probably narrow it down.
Dodge Bros used one with a center like that in the '20s but it was not a floater like a big truck. Alchemy I believe has nailed it.
Back in my dirt track racing days I spent enough time rambling thru country junk yards looking for these rear ends that I can say that Alchemy is definitely 100% correct. Early ones from Ford had a "wide 5" bolt pattern, and they changed to the 8 bolt pattern in early 40s. I believe the Studebakers all had 8 bolt.
I hate to muddy up the waters but it seems to me like I have seen older 4x4 conversions that used drives like that.
66? Was GMC using the 55-59 cabs that late? I kind of doubt it, but they did some strange things. Neat truck. I don't know anything about the rear.
Looks like the same rear end from under the 1952 ford f2 I once owned, geared very low. Studebaker had a large five and six lug pattern on 3/4 - 1 tons , never seen one with stock 8 lugs. I would say late 40's - early 50's ford, they used 8x6.5 bolt pattern and where full floating like that one.
It's referred to as a Timken, as others have stated, used in Fords & Studebaker 3/4 ton trucks. It was also the basis for champ quickchange rear ends, the removable housing was used in pairs, along with the carrier. I have one that Frankland welded a plate on the back, and added a lower shaft, for an early quickchange conversion.
Marty......your comments bring back memories of the second dirt track stock car we built in 1966. Thought we had to have a quick change, so we bought a well-used 3/4 rear end like this that had the early Frankland conversion. We could never get bearings to stay in the aluminum Q/C cover. I still have several of the original failed covers as reminders to never buy well-used drivetrain parts. We got a decent sponsor later in the season and used most of the money to buy a new style Frankland 3/4 quickchange with a new aluminum center section. Those were the days !!
Well I am going to say that the rear that the OP showed in post 1 under the 66 C10 got there the same way the one did that is under the yellow mid 50's GMC 550 that Jeepsterhemi posted. That was what they had available that day when they needed a rear axle to put under the truck. The "we can cut it out of that old _____ and change the pads and have it under the truck in a couple of hours" thing.
I think I have seen that rear end under some late 40's and 50's Willys trucks. I don't remember if they were 4 wheel drive, but I think they were.
My old 48 Willys pickup had that timken rear. Yes BJR 4x4 with 5.38 gears. But the Willys were 5 lug.