Need to override the forced Aspect Ratio in 7.1 Image blocks. Anyone know a code?

Can someone help provide a code to enter into Custom CSS that overrides the Aspect Ratio in the Grid Simple layout in the Image blocks in 7.1? Help! The workaround is super tedious and I do not want to use the Grid Strips layout. Anyone have a code that currently works to override this and allows the images to remain true to size in the main portfolio page in your navigation sections? Do I need to remove code that Squarespace has put into place before I can add one that overrides this? 

The goal is: I want to use Grid Simple in my 7.1 Image block in my navigation pages (they're a portfolio)  but I don't want it cropping any of my images in the main portfolio view.