That X member can be removed and replaced by another, but due to the way its built and bolted in, it's not safe to cut it, for the same reason that these cars are not a good candidate for a front clip. The hat section frame rails will eventually crack up if they are welded. It's as much the metallurgy as the configuration that's the problem. A bolt-in X member is the way to go if you insist on "modernising" it.