Well I can't find any real dyno charts for the Duramax so far... but this one at hypertech shows what they measured on their chassis dyno good for 2001-2004 6.6L turbo diesel:
http://www.hypertech-inc.com/images/...uramax0104.jpg

And you can see if that coincides with the one at edge products... it won't come up on my computer for some reason so I can't check:
http://www.edgeproducts.com/chevy_duramax.html