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Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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| | | | Joined: May 2006 Posts: 8,351 'Bolter | | 'Bolter Joined: May 2006 Posts: 8,351 | It is an Eaton. There are no aftermarket gears available for them. If it's from a 1 ton, it's a 5.13. 3/4 ton are mostly 4.56, though some did have 5.13s and there was a 4.10 option for the very late ('68-'72) version.
Bill Burmeister
| | | | | Joined: Jul 2010 Posts: 21 New Guy | | New Guy Joined: Jul 2010 Posts: 21 | | | | | | Joined: Jul 2010 Posts: 21 New Guy | | New Guy Joined: Jul 2010 Posts: 21 | | | | | | Joined: May 2006 Posts: 8,351 'Bolter | | 'Bolter Joined: May 2006 Posts: 8,351 | I stand corrected. I still beleive it's an Eaton, though. There should be a stamped ID marking on the front face of the 3rd member, usually on the right side, though it could be on the top of the snout. Might be able to tell for sure with the codes.
Bill Burmeister
| | | | | Joined: Jul 2010 Posts: 21 New Guy | | New Guy Joined: Jul 2010 Posts: 21 | I'm sorry, but I can't find any markings on the castings. | | | | | Joined: Aug 2004 Posts: 1,418 ODSS Lawman | | ODSS Lawman Joined: Aug 2004 Posts: 1,418 | The castings in a GM rear end will be located on the passenger side of the front of the differential where the driveshaft/torque tube goes into the rearend.
SWEET Sergeant At Arms: Old Dominion Stovebolt Society BUNS?!?!?!Where we're going, we don't need no buns.....1950 GMC 450 1951 Chevy 1/2-TonThe GreenMachineIn the Stovebolt Gallery | | | | | Joined: Jul 2010 Posts: 21 New Guy | | New Guy Joined: Jul 2010 Posts: 21 | | | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | Bill,
What makes you say it's an Eaton?
I've torn apart at least a half dozen of these rearends and I can confirm they are GM. I did the 5.43 upgrade to my COE a year or two back.
I don't know where the flange w/that seal in pics 2 and 4 came from. It shouldn't be from this rear end.
Jeff | | | | | Joined: Jul 2010 Posts: 21 New Guy | | New Guy Joined: Jul 2010 Posts: 21 | Jeff where did you find the 5.43 ring and pinion? | | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | I found it at a warehouse that dealt with NOS ring & pinions and drivetrain related parts. No more available unfortunately, I got one of the last sets. If I can find the interchange part numbers I'll post them.
Jeff | | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | Oh yeah, as I'm sure you know, they are extremely rare for the open driveline 1 1/2 ton rear ends. The 1940 and older torque tube 1 1/2 ton trucks are still fairly rare, but more often available.
Jeff | | | | | Joined: Jul 2010 Posts: 21 New Guy | | New Guy Joined: Jul 2010 Posts: 21 | OK I found a 5.14 out of a GMC. Will it fit? | | | | | Joined: Jul 2010 Posts: 21 New Guy | | New Guy Joined: Jul 2010 Posts: 21 | Will a 1950 GMC 5.11 fit in my truck? | | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | I replied to the other post of yours, and it occured to me, the 5.14 is out of a 1 ton rear end and will not fit. They did not make a 5.14 for 1 1/2 ton rear ends.
Jeff | | | | | Joined: Jul 2010 Posts: 21 New Guy | | New Guy Joined: Jul 2010 Posts: 21 | Well I found the 5.43 and it's in. Onward and upward. | | | | | Joined: Feb 2006 Posts: 1,867 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 1,867 | Sweet!  | | |
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