Slapper Bars

In the late 80's, I briefly had a '68 340 dart, auto, 3.91 sure grip with traction bars. Biggest bias plies you could get under it. When you punched it, the whole car would come up evenly several inches, then take off forward. Always wondered if that's how traction bars were supposed to work...

They help the rear suspension push the tires down into the pavement, which lifts the rear of the car.