Scaling Reference Base Files but only the Y-axis?

Hello community,

I'm doing roadway striping plans. I've referenced in the base files at 40 scale. Horizontally It captures the right length I want  of my sheet model (Let say 400' so).

Vertically I want to exaggerate the roadway so It'll be better for other people to see. Is there a way to do it. I tired scaling the reference files but it 

will scale both x and y axis. I don't want to add more sheets. I just want to scale the y axis of the reference files/base files. Thanks for reading!