Can you install the heads and valve covers from a LLY or LBZ on a 2004 LB7 engine solving the fuel injector leak in your crank case problem. This will give you a Duramax with out the EGR and Cat head achs.
the answer is yes...it can be done with the right parts and proper tuning...if you are fluent in EFI live or can afford to have someone custom tune it for you then you should be able to complete the job...a couple of people are working on this for themselves and at least one known completed one...