I have a 2009 Express van with a Duramax diesel and bent frame and I have a 1999 with good frame. I'm in CA so rust is not an issue.
Can I directly swap the frames, are there any differences?

 

Good question.. that may take some research on your part. Items to consider..... Is the 1999 a 3500 van and same wheel base? Did GM modify the frame for the diesel? Sounds like one heck of a project.

 

That's a very interesting question I'd like to know the answers on. I am only guessing, but I assume they are the same, with perhaps some minor differences in hole locations for various mounts. As the design evolved, new modules and options were probably introduced right to the frame itself.

This interests me because it's on of the things I like to day dream about at times. If my life was different and I didn't buy this new van, I think a fun project for me would have been to buy an old van or two, completely lift the body and build a work truck that would last for years and years. Take everything apart and coat everything in rubber. Re-assemble.

This seems like a lot of work, but I was reading that it's one of the BEST ways to change the motor. Lift the body off the frame. That motor you have in the 09 is probably worth more than the old van you want to install it in. I'd still like to learn if it's possible to put a small inline diesel in these vans. I'm starting to think more and more it would be possible.

I think your idea is probably worth pursuing if you have the means. Obviously a lift would be ideal. Unbolt the body, disconnect the harness'es and hydraulics and then start changing everything over. I'd try installing the new dash. You'll probably need to move the BCM and harness'es over too. If you go this route and get this far I am collecting as many schematic diagrams as I can for these vans. Although my interest is obviously primarily 2014.

 

2003 got a stiffer upgraded box 3 pc box frame.....so no.

Both the Express and the Savana offer a driver's-side rear-door option for 2003--or, to be more accurate, doors: a pair of them, side-hinged portals that open clamshell fashion from the middle, 60/40, just like the pair on the opposite side of the vehicle. No sliding doors here. It's amazing how much this innovation--a first in full-size vans--improves access to the interior. Which makes it even more amazing that no one's done it before. But then people probably said the same thing about the Hula Hoop.


The left-side-door option isn't the only improvement to the Express and Savana. GM's big vans have new (and, of course, stiffer) three-piece box-section frames, updated editions of GM's Vortec V-8 truck engines, a four-wheel-drive option, all-disc brake systems with anti-lock brakes as standard equipment, upgraded interiors, an OnStar option, and a modest face lift, to hit the highlights.

 

Well, that answers that. I am glad you spent the effort. The Left Hand side doors, since you mention it... I think it's a complete shame that it's no longer an option (E26). I love mine. I am so glad I traded vans to get it.

 

Even though, I don't know the specific differences between the frames.....

 

I don't know how these vans hold their value in California, but here a 2003 to 2007 can be had fairly cheap. It would be a lot of work though. Fun for the experience if you like challenges and have the resources.

 

Both vans are 3500, 155" wheelbase. So no driver side doors here.
The 2009 diesel is an ambulance with 250k miles, with high top, dual alternators, never towed before, nice interior. Would make a terrific camper van.
The 1999 is only a frame donor I can buy for $300 off craigslist, no drivetrain or paperwork. I want to keep the diesel registration of a 2009. I didn't see the VIN number on the frame anywhere.
Yes we will lift the body up, and then I plan to transfer everything from new frame to old straight frame. Much easier access to everything this way.

Also, what does 3 piece mean? There's a tranny crossmember that you can unbolt but the frame itself is 1 pc.

 

From memory, the rails on my 2014/2015 are a box, not a C channel or anything like that. It might be folded and welded out of three pieces, or it could have two dividers created the effect of three boxes. I don't know, I am just typing. I like the sounds of the ambulance, but you know... I think in light of the thread, you should look for another newer donor frame. There must be a 2003 or newer with a dead drivetrain somewhere there in California. These vans are EVERYWHERE here.

I'm not really sure the left hand would make a difference. Too bad I don't have both vans, I'd park them side by side. I think you should go for a newer frame to be safe as what the other poster said and because when I look at mine, schematics, etc., I know there are things bolted on there that didn't come in pre-2003. I have dual hydraulic lines, does your donor? There will be holes and attachment points your going to want that the pre-2003 will not have.

Just grab a newer donor that's all.

PS> There is a Serial Number somewhere there on that frame. Don't kid yourself. They are all over today's vehicles. Some are identified and well known, others are in hidden spots.

 

So yes so far everybody was right. The frames were completely different - front suspension big changes. Engine mounts are totally different- I ended up driving 80 miles each way to look at it but I did not purchase it.