I know that the 2003s have a completely different wiring setup than the 2002s. I have a Duramax swap project in mind in the next year or so. I'm trying to figure out if I'll create a lot more headaches by salvaging a 2003 and up versus a 2001-02. Has anybody worked with one yet? The reason I post it on the project page, is because my project is very close to this one. I'll be installing a Duramax into a 92 K-Blazer.