Anyone used the aftermarket power brake systems that mount under the floor for a 1950 Chevy?

I'm helping build a 1/2 ton truck and trying to use one and the brake pedal and lever don't come close to lining up with the original hole.

When we called the maker we were told we would have to cut a new hole in the floor for the lever to go through, and that we would have to cut the pedal mount off, and reweld it in another position to make it work. And we would need another "patch panel" or "two piece cover" to seal it up. And of course it cost extra plus the shipping.

This set up was not cheap. Yet we're having to mess things up to "make" it fit.