Just to clarify with quickie spotting:
EMD GP35: Prototype is 52'2" long, 4-wheel trucks. This is the model American Models makes and has been offering since 1992.
EMD SD35: Prototype is 60'8" long, 6-wheel trucks. (If one were made in S scale, which it's not, that would be about 3/4" longer than the GP35.)
And that's the Real News.
Rusty