If you have a 70 or up Cuda there is a brace-strut from shock tower to cowl, it’s not that strong but the inner fender and the strut are a good engineered piece for street duty. To keep from flexing you need an X arrangement clear back to bottom of main hoop, a lot of bars and less wiggle room in car. BTW the cowl is not strong enough because the uni-body was designed to flex from the get go. Don’t flex it breaks.