Before i burn....

i got a (E) version of Duke nukem 3D and i was just wondering if it will work on a US Saturn if i just make the region code U

Unlike the SCD version of the conversion program, Satconv has no problems with different regions. The only problem you might encounter is if DN3D is PAL optimised. If this is the case, the game will appear too big for the screen and run too fast.
The US copy I have is version 1.018 and the Euro is version 1.014.

This makes me think it would be PAL optimized. I can double check it later if you like.

It could always be that someone changed a Euro version to US with Satconv though... ???