from what I remember , on the original motor mount, if the molded rubber broke free from the metal, the engine was free to raise up quiet a bit
the redesigned motor mount had a tee shaped metal safety catch built in, so if the molded rubber broke free from the metal, the engine did not raise up as much.
It you replaced the original motor mount with the new design you did not need to reinstall the safty cable.
I remember replaceing some of these when I worked at a service station in high school. The machanic hated doing them so would save them for me to do.
The test for a broken motor mount was to raise the hood, start the car, put it in gear with brakes on, and gas it. Then watch how high the engine would torque up. Looked like the engine would pop out.