He is talking about the next crossmember back from the tranny crossmember. The DS and exhaust are plumbed through it and it is welded to the frame.

If it is hopeless to straighten or you can't live with it, it is going to require cutting it out and rewelding a new one it.

You can go tube if you want. Just fab up mounts (bolt on or welded) and go from there. CPOM has some good pictures of what he did. While not specific to a trooper or that crossmember, it will give some ideas of how to do mounts and whatnot.

Good Luck,
Michael