Except for the NASC is there any substantial difference between the SD70 and the SD70M more specifically would there be anything else required to a 70-kitbash besides splicing the nose from one of Kato's N-Scale SD40-2s onto one of their SD70M bodyshells?
From the far, far reaches of the wild, wild west I am: rtpoteet
It will take a little bit more work to get the SD40-2 nose to look exactly like a nose on an SD70. Take a look at a photo I have here of an IC SD70.
Near the front of the cab there is this duct working that extends out of the nose (Someone more knowledgeable will have to tell you what that is). The sub cab on the SD70 is also different from an SD40-2 on the engineers side. Other than that there are not many noticeable differences between an SD40-2 cab and an SD70 cad.
I can upload more photos of the SD70s cab if you would like.
My Youtube Channel: http://www.youtube.com/user/JR7582 My Flickr Photos: http://www.flickr.com/photos/wcfan/
I think I would use a ATLAS SD50 or 60 to do your SD70M/70 conversion if for no other reason that the price of the needed parts.Buying the hood, walkway ,cab and railings from ATLAS would be less thasn half the cost of the KATO parts.
To be 100% accurate you will still need to modify items like the battery boxes and short hood.