GMT400 History

[leeezard7]

1991 K3500 was the only year for the 4l80e and np205 combo. and im not sure but think it was only available in a cclb.

 

[outalne94z71]

1991 K3500 was the only year for the 4l80e and np205 combo. and im not sure but think it was only available in a cclb.

yes 91 only in the 73-87 body style that the cc had till 91

 

[eric.s.t]

I was trying to figure out why a GMT-400 is called a "gmt400" and also, why are we OBS.. what makes us original ... i know theirs oobs... or even nbs and nnbs.... thats it going to be after that.. nnnbs? gmt1000?

 

[1badgmc]

I was trying to figure out why a GMT-400 is called a "gmt400"

Because that's what the internal designation for the platform these trucks are built on is called.
'99-'06 is GMT-800 because that's what GM calls it.
'07+ is GMT-900 because that's what GM calls it.
The next generation is doing away with the GMT-### naming system. I just read the other day what it's being called, but I don't remember where I saw it or what it's called. But it will be called that because that's what GM calls it.

and also, why are we OBS.. what makes us original ... i know theirs oobs... or even nbs and nnbs.... thats it going to be after that.. nnnbs? gmt1000?

The OBS and NBS nicknames began when a lot of the original truck forums were really starting to begin to pop up. Most notably it came from www.FullsizeChevy.com FSC began in 2001. When it began, nearly all of the membership owned GMT-400 trucks or the brand new GMT-800 trucks. It was just easier to type OBS or NBS when referring to these trucks. It may have been short-sighted to use those abbreviations, but that's just the way it played out and the names were solid for another 6 years.

I've never subscribed to the OOBS or NNBS stuff. To me, those are square bodies and GMT-900s respectively. I usually use the GMT-800 designation for the "NBS" and have been trying to use GMT-400 for our trucks, even though they will forever be "OBS" in my eyes.

So many people get annoyed, confused, upset or simply think the OBS and NBS terms, but the fact is they exist and now you know why. Just go with it. Resistance is futile. You will be assimilated.

 

[RHamill]

Because that's what the internal designation for the platform these trucks are built on is called.
'99-'06 is GMT-800 because that's what GM calls it.
'07+ is GMT-900 because that's what GM calls it.
The next generation is doing away with the GMT-### naming system. I just read the other day what it's being called, but I don't remember where I saw it or what it's called. But it will be called that because that's what GM calls it.




The OBS and NBS nicknames began when a lot of the original truck forums were really starting to begin to pop up. Most notably it came from www.FullsizeChevy.com FSC began in 2001. When it began, nearly all of the membership owned GMT-400 trucks or the brand new GMT-800 trucks. It was just easier to type OBS or NBS when referring to these trucks. It may have been short-sighted to use those abbreviations, but that's just the way it played out and the names were solid for another 6 years.

I've never subscribed to the OOBS or NNBS stuff. To me, those are square bodies and GMT-900s respectively. I usually use the GMT-800 designation for the "NBS" and have been trying to use GMT-400 for our trucks, even though they will forever be "OBS" in my eyes.

So many people get annoyed, confused, upset or simply think the OBS and NBS terms, but the fact is they exist and now you know why. Just go with it. Resistance is futile. You will be assimilated.

Everything in this post is completely accurate and should be posted on the main page. Or even better yet, on Googles home page.

 

[RHamill]

Because that's what the internal designation for the platform these trucks are built on is called.
'99-'06 is GMT-800 because that's what GM calls it.
'07+ is GMT-900 because that's what GM calls it.
The next generation is doing away with the GMT-### naming system. I just read the other day what it's being called, but I don't remember where I saw it or what it's called. But it will be called that because that's what GM calls it.




The OBS and NBS nicknames began when a lot of the original truck forums were really starting to begin to pop up. Most notably it came from www.FullsizeChevy.com FSC began in 2001. When it began, nearly all of the membership owned GMT-400 trucks or the brand new GMT-800 trucks. It was just easier to type OBS or NBS when referring to these trucks. It may have been short-sighted to use those abbreviations, but that's just the way it played out and the names were solid for another 6 years.

I've never subscribed to the OOBS or NNBS stuff. To me, those are square bodies and GMT-900s respectively. I usually use the GMT-800 designation for the "NBS" and have been trying to use GMT-400 for our trucks, even though they will forever be "OBS" in my eyes.

So many people get annoyed, confused, upset or simply think the OBS and NBS terms, but the fact is they exist and now you know why. Just go with it. Resistance is futile. You will be assimilated.

Everything in this post is completely accurate and should be posted on the main page. Or even better yet, on Googles home page.

 

[88GMCtruck]

Double post = double the importance.

What he said is exactly true. Back when I was one of those OBS / NBS term users, although i've always called 73-91 squarebody. Once the GMT900 trucks debuted I began calling them by GMT platform name.

 

[96-1500]

Not sure if anybody else chimed in on this, I didn't feel like reading through all 14 pages.

"1500/2500s used a semi-floating rear axle and 3500s used a full-floating axle."

Any 1500 HD (F44) or 2500 LD truck with a 14-bolt and 6-lug axles was semi float. Some 8-lug, 8600lb GVW 2500 trucks had semi-floating axles, many (I would guess most) had full-floating axles. I've seen two completely identical K2500s from the same year with the same options, engine, everything, but one will have a SF one a FF. Mine happens to be a SF (see sig, it's an 8-lug, 8600lb K2500).

I don't know whether this was something you could order from the factory, or just whatever GM decided to throw in there. Seems strange to me.

 

[96-1500]

Also a question...
What exactly encompassed a Z71 package? I know shocks, skid plates and locking differential, but was there anything else? The reason I ask is, I own two K2500s, one for parts, one is my driver. My driver is a Cheyenne model, plain jane. The other one (basically identical, both are 1996, ECLB, same colour, gear ratio, engine, transmission etc.), is a Silverado option, with power windows, door locks, transfer case etc. It was also ordered with skid plates and a locking rear end, unlike mine. However it is badged just as a "4x4" like mine is. I'm assuming it's basically just the same offroad package as what "Z71s" had, but they didn't do the whole sales gimmick thing as much with the 3/4 tons. Anybody have any idea whether this is true or not? I've seen 3/4 tons badged as Z71 but I'm guessing they just put the sticker on there.

The whole history there seems a little hazy and inconsistent. Not that it really matters, I'm just curious.

 

[ChrisAU]

Also a question...
What exactly encompassed a Z71 package? I know shocks, skid plates and locking differential, but was there anything else? The reason I ask is, I own two K2500s, one for parts, one is my driver. My driver is a Cheyenne model, plain jane. The other one (basically identical, both are 1996, ECLB, same colour, gear ratio, engine, transmission etc.), is a Silverado option, with power windows, door locks, transfer case etc. It was also ordered with skid plates and a locking rear end, unlike mine. However it is badged just as a "4x4" like mine is. I'm assuming it's basically just the same offroad package as what "Z71s" had, but they didn't do the whole sales gimmick thing as much with the 3/4 tons. Anybody have any idea whether this is true or not? I've seen 3/4 tons badged as Z71 but I'm guessing they just put the sticker on there.

The whole history there seems a little hazy and inconsistent. Not that it really matters, I'm just curious.

Yeah, Z71's were only available as a half ton package. All the stuff was available for 3/4 tons, but no need to market a Z71 package to the 3/4 and 1 ton markets.