This retrofit column is designed to fit your 1958 Chevy Impala and does NOT require modification to your original vehicle to install. Simply remove your old column, saving your original under dash mount and floor mount. This column will match the dash perfectly using the original bezel.Steering Wheel Adaptor Required (for Aftermarket Wheel)1969 or Newer GM Passenger Car.3, 5, 6, and 9 Bolt patterns available.