a friend did same thing in his 69superbee
him and his buddy had just installed a new drag clutch what kind escapes me as I was young and dumb
they are doing burnout in the driveway,their story they heard a hi pitched whine just as it let go causing them to pull their feet back as they leaned forward to hear the noise better ,the fragments cam through the floorboards,sticking in the dashwhere their feet would have been no injuries except the superbee. true story I saw the hole in the floorboards and the decimated bell housing a few days later.