I'm 6ft 5in and trying to get some head clearance for a helmet, I don't have a cage yet but even mounting my bucket to the floor with side mounts my head hits the roof. So I've been looking into it and seen where some people have made custom floor pans to sit lower for tall people in little cars and didn't know if anyone had looked into it with an FC. My car is a beat up 88 convertible missing the headliner in the targa top.

This photo is for reference to show how much headroom I have.