Atlas is offering a new rendition of ALCO's RS3 road switcher. Among other features, the model includes two options: water cooled turbo exhaust stack or air cooled turbo exhaust stack. The water-cooled stack runs 90 degrees to the axis of the carbody whereas the air-cooled stack runs parallel. In order to be prototypically correct and model the PRR RS3 accurately, my question is, which exhaust stack would be appropriate? In my research so far, it would appear that the PRR rs3's were equipped with water cooled turbo exhaust stacks.