What is this????

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SeanV

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Hey guys, need a little more help identifying what I’ve got. The truck is a 77 C20 Suburban that appears to have some of the stock suspension components taken off. The previous owner lowered the truck bu way of spindles and converted to 6 lug rotors. The rear end is a truck 12 bolt, but I’m trying to identify what it actually is. It’s got a very long vent hose on it making me think it’s from a 4WD truck. It’s got this circular ear on the passenger side of the housing. Any idea what this is from?
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78C10BigTen

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Thats either an older truck rear... (60s) or car rear from like a monte carlo, malibu
 

SeanV

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It also has casting K13 8 on the driver’s side rear of the housing. You can see 123456789 under that weird eyelet. And GM 51 on the passenger side of the pinion section.
 

SeanV

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Thats either an older truck rear... (60s) or car rear from like a monte carlo, malibu
Even with just the one eye? Could that be where the panhard bar would’ve gone? I have more pictures if needed.
 

78C10BigTen

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Even with just the one eye? Could that be where the panhard bar would’ve gone? I have more pictures if needed.
Im not 100% sure. @bucket may know closer then me. Theres other rear smart guys here to comment that i bet havent seen it yet.
 

78C10BigTen

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Post a pic of the other side where the eye would be?
 

SeanV

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This is about the best one I have. Also one from the front look aft at the eyelet.
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78C10BigTen

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This is about the best one I have. Also one from the front look aft at the eyelet.
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Im sorry i shoulda specified... the opposite side of the rear... (left to right). So from the back im interested to see the left side of the rear where that ear would be. Id like to see if somebody custom cut it.
 

SeanV

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Yes sir, that bottom picture is of the opposite side (drivers looking forward). It doesn’t have anything of the sort like that eyelet on the passenger side of housing.

Do you need a better picture?
 
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RecklessWOT

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Do you have a picture of the whole rear cover? The cars and trucks were very different shapes. And from my understanding the car axles were actually better than the truck axles.
It's weird that one eyelet and being straight like that, usually there was one on each side and they were angled towards the front of the car. I'm sure there are dudes here who know a lot more than me
 

bucket

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I'm not real familiar with them, but that big eyelet should make it a pre-'73 truck rear, specifically for a coil spring setup.
 

45acp

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A Chevrolet parts dept. can ID that. On the RH (Passenger side) tube about 5 inches from the housing on top there is a 3 lettered code stamped on the tube. Sometimes it can be a real bear to find, a person hand stamped it. They will be able to tell you the year and what it came out of and what the gear ratio was from the factory. As I said it can be a bear to see but it's their. Brake clean/wire brush and a mirror are your friends.
 

eskimomann209

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Looks like the 12 bolt on the 69 I just cleaned up. Guess is it probably was from the coil sprung rear. Someone probably welded some leaf perches on cuz that’s what they had laying around.

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SeanV

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I'm not real familiar with them, but that big eyelet should make it a pre-'73 truck rear, specifically for a coil spring setup.
That’s what I thought too. But it’s installed on leaf spring rear suspension. And, if this helps, it has 5 main springs in the pack plus the overload spring for 6 total. They’re 2.5” wide and 2.2” thick. Isn’t that a 4x4 1/2 ton set up? It’s clearly not the factory unit, but I’ll get a better picture of the pumpkin today. It looks to be a generic GM 12T truck housing save for that goofy eyelet thing.
 
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eskimomann209

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Well the 1/2t 2wd axles were 6 lug until like 70 or 71.
The spring perch distance remains the same for 4x and 2wd and the lead count goes more toward 1/2 ,3/4 or 1ton.
I think the WMS changes between the 2wd and the 4x. But I’m not 100% sure on this one.
Maybe measure it. And I’ll compare it to this axle which is a known factory 2wd 1/2t
 

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