torque box reenforcement

Hey guys so about a year ago i picked up a 1989 lx hatch and recently my torque box has torn the car sat somewhere for a while so it’s a bit rusty underneath but it’s cracked in half and it’s cracked the floor, how should i go about fixing this? a friend of mine said he could make me a brace...

I did a search and didn't find anything. Are the torque boxes weak on the 94+ cars like they are on the 79-93 Foxes? I want to know if I will need to upgrade them on my Cobra or not once I get DR's for it.