When replacing the frame rails after the new torque boxes are installed does the new firewall need to be in first? Or does the frame rail weld just to the box and then the toeboards that go over the torque boxes? In other words do the frame rails weld to the firewall at all? And can you re-use the old shock towers after removing them as long as there is no cracks or rust damage? And do you think i even need to replace the firewall or will the toe boards cover the missing steel or a pair of firewall to floorboard pannels do the trick? Thanks in advance.