2655 - 1970-1981 GM F-Body Lower A- Arms, Race VersionOptional New Hardware Kit: UMI offers the option of new high grade mounting hardware for your classic Camaro or Firebird. 1970 1974 cars use standard hardware while 1975 1981 use 14mm metric hardware. UMI suggests checking the current hardware size before ordering to confirm. UMI a arms are supplied with both sets of mounting sleeves to accept either hardware sizes. Hardware kits are Grade 8 standard and Grade 10. 9 metric with Ny lock nuts.