K2500 New body gmt800 frame swap

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Jayss88

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Doing a modified restoration on a 94 k3500 srw rclb. Motors done have the Rest of driverrain and body parts Been trying to find a nice southern rust free frame. Tried searching and im wondering if anyone hase ever pulled off a new body style gmt800 2500hd frame swap in one of these trucks. They are alot stiffer, stronger better brakes ect. The pros are obvious not to mention they are everywhere. Any insight on how much of a nightmare. These older frames are weak and Ive done a ton of work built a 509cuin big block absurd amount of money spent on the body. Not concerned with getting my hand dirty and have any fab tools and skills needed. Just wanting to find out what kind of major hurdles aside from the obvious before i get any further into an idea like this
 

Brother Al

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Unfortunately, I cant answer your question, but I can offer another idea. I am doing a frame swap on my '92 ExtCab Stepside K1500. Took me awhile to find a good core and it was off a '98 that had minor rusting of the 2 rad mount pads. Also discovered the extra angular brace on the engine cradle is cracked, seemingly from a poor weld job by some UAW back in '97. I compared pics of a bare GMT800 and a GMT400. GM clearly re-used the layout but with improved/additional bracing in a number of key areas, BUT! Based on my personal experiences with GMT800's, GM cut the quality of the steel being used...There are tons of them that look horrible, far worse than any GMT400 did in the late 90's/2000's with similar age and miles. My guess would be that GM reduced the nickel content when the metal prices skyrocketed in the 2000's, (ie losing billions each year in the 2000's).

Anyway, my solution is boxing portions of the stock framerails, with opposing pieces from another GMT400 frame, adding tubular bracing, and welding up the stock weld spots the UAW workers missed/skipped. Just to be clear, Im cutting sections off the front half of a GMT400 frame and welding them to the inner sides of the base frame, passenger side section used on driver's innner, etc. The rear section is a bit trickier, because many are pretty nasty up here, so I might just need to have some sheet cut to size.
Bracing is fairly straightforward, Im pretty much copying what GM did to the middle section of the GMT800 frame, adding "flats" to the bottom of the spare tire "K" brace, and replacing all of the crappy formed steel U channel with tubular steel.
I also scored a set of stock '95-'98 GMT400 forged lower control arms from a K2500/K3500, and am contemplating the GMT800 front brake & knuckle swap.
 
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Jayss88

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Im deffinetly with you on the quality of steel in 1500 gmt 800 but a 2500hd frame ismuch taller thicker and beefier then a 1500. Im not gonna do anything that starts out rusty either so thats outta the question. My 2 options are get a clean 93-00 k2500/3500 frame and box/brace reinforce everywhere. Or get a 01-2010 2500hd frame and make my 94 body fit on it. My main concern is finished product having jacked up fitment issues. Its gonna be a frankentruck either way just want it to look factory but stronger when im done
 

BowtieBrody

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It'll be easier to just find a GMT400 frame to swap, you'll have to do so much cutting, grinding, re-mounting, and shoe-horning to get the 400 cab and bed onto the 800 frame, you'll more than likely lose a lot of the frame's structural integrity;
 

leakers

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It'll be easier to just find a GMT400 frame to swap, you'll have to do so much cutting, grinding, re-mounting, and shoe-horning to get the 400 cab and bed onto the 800 frame, you'll more than likely lose a lot of the frame's structural integrity;

How so ?
Have you done this or are you just surmising?

I have helped with fitting a C3500cclb 1998 GMT 400cab and bed on a 2005 frame and it was more or less a bolt up physically. I cannot remember the exact details of the few minor modifications as I was only assisting someone else during a visit to Vancouver, BC 9 years ago, but It was in the order of mixing and matching body mount rubbers, and bolt lengths , making a hybrid rad support panel,( using some pieces from the early and later ones ,) changing the exhaust system , wiring etc etc, but the actual engineering was minimal. maybe bumper mounts, and some bolt holes needed re positioning , from memory NO cross members or main rails were removed or replaced.

My take is that although the steel MAY be lighter spec the boxing and extra structural engineering will still be stronger, and is designed with MODERN crash and crush collapsible safety engineering.
We did it so the truck could arrive in NZ, Duramax powered with paperwork for local registration . I was not there for the final assembly , but I have seen the truck since it arrived here and it looks STOCK , very hard to see any modifications at all.
I have also seen a 1997 2500 three door body on a 2008 frame done by the same guys and it also looks stock... both inside and underneath.
Actually I think the body mounts were higher, and the rad support mods were made to lift the body so the hood would close over the Duramax, and that a filler panel from a HD truck was used between bumper and grille.
 

BowtieBrody

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How so ?
Have you done this or are you just surmising?

I have helped with fitting a C3500cclb 1998 GMT 400cab and bed on a 2005 frame and it was more or less a bolt up physically. I cannot remember the exact details of the few minor modifications as I was only assisting someone else during a visit to Vancouver, BC 9 years ago, but It was in the order of mixing and matching body mount rubbers, and bolt lengths , making a hybrid rad support panel,( using some pieces from the early and later ones ,) changing the exhaust system , wiring etc etc, but the actual engineering was minimal. maybe bumper mounts, and some bolt holes needed re positioning , from memory NO cross members or main rails were removed or replaced.

My take is that although the steel MAY be lighter spec the boxing and extra structural engineering will still be stronger, and is designed with MODERN crash and crush collapsible safety engineering.
We did it so the truck could arrive in NZ, Duramax powered with paperwork for local registration . I was not there for the final assembly , but I have seen the truck since it arrived here and it looks STOCK , very hard to see any modifications at all.
I have also seen a 1997 2500 three door body on a 2008 frame done by the same guys and it also looks stock... both inside and underneath.
Actually I think the body mounts were higher, and the rad support mods were made to lift the body so the hood would close over the Duramax, and that a filler panel from a HD truck was used between bumper and grille.

I'm just echoing everything I've ever been told, as I was wanting to research a K1500 body swap onto a later model chassis and was told it was more effort than it was worth; if OP wishes to attempt the swap, there isn't anything stopping him, I'm just some dude from the internet trying to lend thoughts to his idea.

Intriguing about this body swap, do you have any documentation on it? Or any links to any more info? The 97 2500 is interesting too as the C/K 2500s never came with the 3rd door option in the GMT400 platform, was it a K1500 cab? You've got me interested in this now;
 
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leakers

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And yet they are everywhere , e.g. http://www.mautofied.com/1997-Chevrolet-k2500_full-size-trucks/listing/100191737/
I know I didn't start or complete either of the swaps mentioned , but I have seen them and touched them..they are real!!! and talked to owners who have actually done the work as opposed to the naysayers who just say it can't be done.... ANYTHING IS POSSIBLE.
If you want to put your 1500 body on a GMT800 chassis , I suggest you go down to a wrecking yard with a tape measure and check it out for yourself.....don't take anybody else's word for it ...in fact it is a life lesson, if someone say's it can't be done prove them wrong....because they are.
I have been modifying and hot rodding cars and trucks since 1968, never seen something that can't be done , safely, if someone puts their mind to it.
Unfortunately American pickups haven't been sold new by franchise dealers in NZ since the fifties/sixties, the rhd supply dried up when the last Canadian provinces changed to left hand drive.
So everything American is privately imported here and we don't always know the fine details about what is and isn't factory, ...however we do have a bunch of trucks here , if they are newer than 20 years old they have to be converted to RHD....expensive and in general a waste of money (30k) so we tend to search the USA for trucks that fit our individual requirements ....or as I said go to the USA or Canada and build something that fits the profile with the matching early paperwork ...If that means putting an OBS body on the running gear that suits the job that's what happens.... The one I mentioned may well be a GMT 400 ,K1500 body on a GMT800 K2500 frame so be it.....The point is it can be done and it is practically a bolt up. I don't have any documentation as none of the trucks I have mentioned belong to me, I don't even know where in NZ either of them are now, 9 years ago ...jeez that is a lifetime ago.
However just for you when my damaged 2015 K3500 truck arrives I will do a build thread as I fit my own 2000GMT 400 cclb body onto it..... and use the 1998 paperwork I have for it ... I am going to need some GMT 400 HD parts , so I will be making a couple of visits :D.
 
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mattillac

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Stubled upon this posted on craigslist, thought of this thread.......

.....This is a 2004 Chevrolet Silverado 2500 4x4 with a 1995 K2500 body set on it. So, everything is an 04 underneath, suspension, axles, lb7 duramax motor, allison transmission, transfer case, everything is an 04. You have all the modern updates and reliability of an 04 Duramax with an old body style look. Titled as a diesel 1995 (so no emissions here) and cheaper insurance than an 04......

https://chicago.craigslist.org/nch/cto/d/1995-chevrolet-k2500-duramax/6239067733.html
 
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