this is back in the 90's. just getting into racing. i was driving my 72 challenger on a weekly basis to the track to have some fun. on the way home one night all of a sudden the motor started to vibrate violently. uh-uo, shut her off and pulled over. after a quick inspection i found that i ripped 3/4's of the lower pulley off the balancer. all the bolts were still attached and it was hanging on by about 1 1/2" of metal. funny thing was the belt was still on