DFX, torque boxes are sheetmetal boxes that the factory used on Hemi and convertible models (in this case, a select few A-bodies) to strengthen the uni-body design and improve handling (factory subframe connectors). These boxes are located behind the front wheels and in front of the rear wheels and link the rocker panels to the frame. Torque boxes were sometimes installed on 440 cars and were a "hit and miss" add-on, depending on what the factory had in stock on a particular day. Even if your vehicle did not have factory boxes, they can easily be added to your A, B or E body Mopar. There are a number of companies that re-pop them - I got a great set from Rick Kruziger out of WI. I searched here on FABO for a string related to torque boxes but not much. A far as I know, a good number of '70 Swinger 340 cars got them but don't know if any 340 Dusters or Demons got them as well. This also made me raise the question of the washers, maybe they indicated that boxes be added to the car... I think I might start a string asking the A-body torque box question - which cars got them etc.