I made a discovery this weekend! [:D]
The fuel/air tank area has always kinda bugged me on the Athearn BNSF SD70MACs. The prototypes have front and rear sight gages and fillers, so I decided to move things around as well as add these items. One of the parts that had to be moved was the air tanks. Going from photos, I could estimate where they had to be moved to, using the handrail stachions on either side as a reference.
When I flipped the shell over, I noticed that there seemed to be two sets of locating holes for the tanks! WOW! One set for the rearward placement of the tank, one for the forward placement. Only thing is, these parts are glued in place. But, with a little effort, I managed to remove the tanks with enough of the pins left to locate them in the proper holes! WOO HOO! I wonder if some effort was in place to model the different configurations between roads. Hmmm…
BTW, the CSX and Conrail models have the single filler so that is correct on those. Unfortunately, the Katos I have have the double fillers w/ the forward mounted air tanks! [banghead]