Another "is the OBS frame the same" thread.

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Strouty

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I am in the middle of a project, well two, or is it three? Anyways, I have four suburbans and I am trying to make two good ones. I have started disassembling two of them and will have access to the frames soon, but I also have two more trucks and wanted to find out if the frames are the same or not. Here is the list of what I have for trucks:

Two (2) 1999 K2500 diesel suburbans (eight lug wheels)
One (1) 1999 K1500 gas suburban (six lug wheels)
One (1) 1997 K1500 diesel suburban (eight lug wheels)

I see people talking about pickup trucks, but I was not sure if the suburbans were different, also the 1500 diesel with 8 lug wheels is a bit of a confusing topic.

Thanks for any input.
 

Supercharged111

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8 lug has different front UCA mounts than 6 lug and different diff mounting. I see you're talking 4wd, so that makes it easier. 8 lug trucks also have thicker frame rails than 6 lug trucks.
 

Supercharged111

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Even when it is a 1500?

You have an 8 lug 1500? I've seen 6 lug 2500, but never an 8 lug 1500 in this older body style. What size front diff is in that thing? 3 bolt or 4 bolt front hubs? Either way, I'm fairly certain the 6 lug vs 8 lug logic would prevail here.
 

88GMCtruck

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From my understanding, my sold the 6.5L 1500 suburban but to keep the cargo and weight ratings acceptable (and probably overall longevity of the drive terrain components as well) they were actually light 2500s hence the 8-lug axles.

I would imagine the 8-lug frames are all the same and the 1500 gas is the differing one.

Take a look through the upfitter info, they do show both C K 1500 and 2500 suburban frames with 6.5L, so based on that at least 3 of your frames are the same...

https://www.gmupfitter.com/files/media/photo/170/1999_LD_CKTruckCurrent.PDF
 

Strouty

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I will be seeing the differences first hand, I bought a rust free K1500 to use the body for my K2500 project. I will have to post some pictures when I get things all apart.


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Supercharged111

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From my understanding, my sold the 6.5L 1500 suburban but to keep the cargo and weight ratings acceptable (and probably overall longevity of the drive terrain components as well) they were actually light 2500s hence the 8-lug axles.

I would imagine the 8-lug frames are all the same and the 1500 gas is the differing one.

Take a look through the upfitter info, they do show both C K 1500 and 2500 suburban frames with 6.5L, so based on that at least 3 of your frames are the same...

https://www.gmupfitter.com/files/media/photo/170/1999_LD_CKTruckCurrent.PDF

Don't forget that the 6.5L turbo 1500 trucks were 6 lug half tons, but did come with the 4L80.
 

Strouty

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Not all of the 1500 trucks were 6 lug, I have one with 8 lugs. Or maybe all the half ton suburbans were 8 lug and the pickups were 6 lug?
 

88GMCtruck

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Don't forget that the 6.5L turbo 1500 trucks were 6 lug half tons, but did come with the 4L80.
Well aware. They used the regular 1500 frames though. I was keeping on subject of suburban frames, since he was talking about swapping them.

Not all of the 1500 trucks were 6 lug, I have one with 8 lugs. Or maybe all the half ton suburbans were 8 lug and the pickups were 6 lug?
1/2ton suburbans with a 6.5L were 8-lug, like i said above likely to keep the cargo capacity within reasonable use. Regular 1/2ton suburbans were 6-lug or 5-lug if 2wd.
 
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