These are the modifications that were made to both the Athearn shell and the Kato chassis.
Here they are with sister units 637 and 976. The ditch lights on the latter has to be replaced with hi ones along a fuel tank upgrade.
I have two corrections to be done on this unit. I have to remove 2 drop grabs on the nose in order to replace the SF marking with the BNSF...
Here is a close up of the fuel tank details. After cutting away the factory cast fuel tanks. The replacement tank and details are from Dteails...
A closer view of my BNSF C44-9W project units.