djras1, considering Casey's swap was putting a diesel from a box van (if I remember correctly) into an H3, not a Duramax into an H2, he really has nothing he can provide you as it's a 100% different swap. And 06 H3's swap was a gas V8 into an H3, also 100% completely different. So no need to get all hurt that they aren't dispensing their wisdom/experience with you, as they'd just be causing confusion with your particular swap goals if they tried.
Seriously, bumping a thread that really does look like it was created to ask for a handout with a swap how to is just bad form on any forum. This forum is incredibly helpful unlike many other forums I have been on. But you cannot expect anyone to simply come along with a full how to as you appeared to be expecting with you initial posts when no one has written one (on this forum at least).
Now, has anyone swapped a Duramax into a H2? Possibly. Have you tried doing a Google search for it? If you have, then you've probably found that no one has done any kind of write up on it. If you didn't do a Google search, then please do one. I'm from the IT industry, and no matter what you are trying to figure out, Google is your friend. If you can't find it on Google, either you're searching for the wrong keywords, or the information just isn't out there on the interwebs.
I've done an engine swap before. Granted it was in a Dodge Neon, but it was still a swap that ended up requiring custom work. My saving grace on it, since it was my first one, was that this particular swap had been done many, many, many times already and there was a very detailed write up about it. However, even though this was something many people had done already, and there was a nicely written up how to on it, I still ran into issues that mysteriously were not covered anywhere, so I had to figure those bits out on my own.
When you're talking about a swap that either hasn't been done, or only one or two people have done it in the world and written about it, you're not going to be able to find a how to, or even compile one from input from others. All you can do is start doing research, like figuring out dimensional differences between the stock engine and the engine you are swapping in, what changes would need to be made to the control system and your gauge cluster and possibly transmission, costs, how much fabrication if any would need to be done, etc, etc.
This isn't an armchair kind of project, because once the metal hits the pavement, you'll run into all kinds of issues you or anyone else ever thought of. So far I have seen absolutely no real input from you on where to even start with this swap. Have you even figured out how everything works in the particular year H2 you want to swap into? I'm betting there are a number of differences inside the engine bay between the different years of H2's, so you really need to start out with the actual H2 you are going to do the swap on. Once you have that, try to obtain a factory service manual for that year, it's worth it's weight in gold in a project like this. Then start getting actual measurements from the actual H2 you are swapping into. See if it will even mount in OK and how much fabrication will need to be done to make it even physically bolt to the transmission and frame. And to do that you have to figure out which Duramax you are even going to use. What year/make/model vehicle is it going to come from? You can't just say "a Duramax" as that's like saying "a Hummer" since there are many variations of the Duramax diesel.
Once you've got the engine picked out, you'll need measurements for it in all 3 dimensions. Height, length, width at several points, where are the engine mounting locations, what is the transmission mounting setup like and is it even remotely the same as the transmission already in the H2 or are you going to use a different transmission? If using a different transmission then that is a whole other can of worms.
Next you need to figure out how you are going to control the engine, and if it will interface with the existing H2's control systems. Casey STILL doesn't have his diesel interfaced with his H3's factory cluster, and I think it's been a couple years now (correct me if I am wrong Casey).
Then you are kind of on your way to getting this done, but it's still going to require an awful lot of time, money, blood (oh, there will be blood!!), sweat, and tears. And possibly a divorce, if you're married.
But really, unless you can find someone that has actually done the exact swap you are thinking of, don't expect a lot of help from anyone. If anyone on here had done anything like what you are talking about, they would have chimed in already. Bumping the thread over and over without contributing a single useful thing to the conversation isn't going to do you any good but annoy the regulars on the forum. Like I said, the guys/gals on this forum are very very helpful. If you haven't gotten an answer yet it's because no one has anything to contribute to that end or has any interest in doing research for a swap they are never going to do.
If you start doing the work (since this is going to be your swap you're going to be doing all of the work, otherwise if you also weren't planning on doing any of the work yourself you'd just pony up the $20,000 or more to take it to a shop that specializes in custom engine swaps) and then ask for help on specific points, then you'd get useful input from everyone. But walking in and just throwing a thread on the forum that effectively says "Hey everyone, I want to do a swap and everyone could provide instructions on how to do this swap, that'd be great" (cue Office Space meme) is getting you exactly what you have seen so far. And if you tried this an any number of other forums (go try this on Pirate4x4 and see how much nicer they are there than here) you'd be flamed until you were a burnt crisp, then they'd resurrect the thread a couple months later and flame you again just to make sure. So you might think people on here are being pricks, but it's far from the truth, whether you want to acknowledge that or not.
