Mustang Two Piece Torque Box (1967-1970) Installation Instructions
1967-1970 Mustang Two Piece Torque Box
This Two Piece Torque Box fits the passenger's side of all 1967-1970 Coupe or Fastback Mustangs.
Years of throttle transfers and exposure to weather can weaken or rust your torque box, which will cause your frame to twist. Replace it with this two piece torque box that sits on the passenger's side of the engine compartment, over the rear of the front wheels, and adds significant rigidity to your Mustang.
This Two Piece Torque Box fits the passenger's side of all 1967-1970 Coupe or Fastback Mustangs.
Years of throttle transfers and exposure to weather can weaken or rust your torque box, which will cause your frame to twist. Replace it with this two piece torque box that sits on the passenger's side of the engine compartment, over the rear of the front wheels, and adds significant rigidity to your Mustang.
Tools Required:
- Spot Weld Cutter
- Welder
- Drill
- 4 lb. Sledge Hammer
Install Difficulty:
- Moderate Project
1. To begin the installation of your new Mustang Two Piece Torque Box, support the car on all four corners with jack stands. Place them under the rockers.

2. Split the two-piece torque box using a center punch. Make sure you are trying to center on each of the spot welds, then make a small indention. Then, drill each of those welds out, being careful not to drill through the second panel. It is easier to install the torque box this way, because you have your alignment holes already there when putting the two pieces back together.
3. Test fit the lower portion of the torque box between the frame rail and the Mustang rocker panel. It may require some persuasion, using a hammer or even a jack to wedge it into place.

4. When it fits acceptably, prep the lower piece by drilling plug weld holes in the area where the lower piece will weld to the front of the rocker, the side of the rocker, and the underside of the Mustang frame rail.

5. Reinstall the lower portion of the box and weld it in. While the photos now only show the Mustang driver's side torque box, the passenger's side installs the same way.


6. Test fit the upper part of torque box. The box should sit on top of the frame rail and line up using the alignment holes you created earlier.

7. When the fit is acceptable, prep the panel by drilling plug weld holes in the are where the top piece of the Mustang torque box will sit over the frame rail.
8. Reinstall the top piece and weld it in using both the holes that were created when you were splitting the two pieces, and the holes that were created in previous step. Once this is completed, the installation of your new Mustang Two Piece Torque Box is complete!
