Z ing a frame means to cut out the center section of the frame between the wheels and re weld it so that the top of the center section is attached to the bottom of the front and rear sections, thus lowering the center section of the frame. In this manner you can lower the body without changing the suspension system. It was a lot cheaper than dropped spindles, cut coil springs, and reversed eye springs. When done correctly, it could also strengthen a frame. It was also called "Stepping" a frame.