here is more info on the chips, edge is probably the best out there for this specific applications, also it comes in an interface, which means you change the power settings on the fly. Edge Products: ProductIt wasn't already posted, and you've been a bearer of great news with each post, looking forward to more.
Wow! That is great, and you can get that from simply switching the chip, you don't need to add any heavy duty parts to it?
If you can bypass all the emissions parts and the EGR it sounds like you can run an essentially 'bare' engine and don't need the complex wiring harness from the vehicle to be hooked up to it in order to run like alot of gas cars do. So basically all you might need is the alternator and charging circuit + power to the fuel pump, the computer which runs the injectors, and a crank angle sensor. Does that sound possible? If so then it could be a real easy job wiring it, and you would be able to eliminate most of the accessory drive belt so Bruce will like it better too.
Also, I read that they will be starting to build a new 4.5 liter version soon. It looks like GM started selling the 6.6 Duramax in 2001. Here's a link to the Duramax forum: Duramax Diesel Discussion Forums
I haven't really dove into the electronic parts of the engine and truck, but if they still keep the engine computer separate from the chassis computer, then yes this is very possible.
Also a neat thing is the newer diesel are throttle by wire which means you don't have to worry about throttle cable.
here is a link describing all the sensors and goodies of the engine.
Duramax Diesel Electronics | Chevrolet Silverado Enthusiast at Automotive.com