torque boxes
The boxes came on Hemis, 4-speeds, and convertables. Not sure of what years they started or stopped, they were welded to the frame behind the front tires, and to the front leaf spring hangers in the rear. I think you will find alot of variables here. I have a real 69 1/2 Roadrunner, 4 speed dana, 60 with no boxes. i have a 69 Dart swinger 340 with no boxes. I have a 70 Dart swinger 340 4-speed that only had 3 of the 4 boxes, and no support plates welded to the floor for the bucket seats to keep the floor from cracking. The factory guys must have gone to lunch and never came back to finish. I added the 4th box and the bucket seat supports.