More than likely its the ES44AC.
Lets See well heres my KCS Roster HO Scale: KCS SD40X-700 KCS SD40-2-3237 KCS GP38-2- 2016 KCS SD40T-2-6101 KCS AC44CW-2022 KCS AC44CW-4594 KCS...
I'm looking for a SD70MAC frame and 1 pair of trucks made my Athearn. Thanks- Damian