Correct hardware can make any installation job easier. These hood hinge bolts are correct for a wide variety of GM vehicles including 1965-72 Chevrolet Impala and full size passenger car models. Can be used for 1958-64 Impala and a wide variety of other applications as a service replacement. Measures 9/16 across flats features hex head with flat tip and a 1 free spinning conical washer. Black phosphate coated. 8 piece bolt set. Specifications:Hex Head Size 9/16Washer O.D