I bought frame stiffening materials from US Car Tool for my 1970 Dart GT and we installed them finishing yesterday. We put in 4 torque boxes and the subframe connectors. Unlike many subframe connectors, these install to the floor of the car like the original subframes so that the floor of the car becomes the fourth side of the box. This is the third car that I have installed them on, one a dedicated drag car - it was a drag car since the mid-70s and already had the factory torque boxes, and the second is the 1970 Dart Custom that is in my avatar. The Custom I have driven many many miles since the install and it really changed the feel of the vehicle for the better. So let's start here with the torque boxes. All the welding was done by Mike Brenno (aka Dr. Big Block) of Wagons of Steel racing here on Vashon Island WA. Mike is a real pro and has done all the installs of this stuff on all of my Darts.
Front box Right side from front
Front box from rear on right side
Front box left side next 2 pics
Rear box right side from back see spring mount on right and subframe overlap on left
Left side from rear, rear box spring hanger on top
left rear box from side, big square hole gives access to rear spring hanger nuts all boxed have a drain hole like the one to the right to keep water from sitting int he box
Front box Right side from front
Front box left side next 2 pics
Rear box right side from back see spring mount on right and subframe overlap on left
Left side from rear, rear box spring hanger on top
left rear box from side, big square hole gives access to rear spring hanger nuts all boxed have a drain hole like the one to the right to keep water from sitting int he box