Direct OEM Replacement – Designed to replace the upper backing plate bolt on 1964–1974 GM disc brake spindles using factory-style components Precise Thread Specs – Features 5/8"-18 right-hand threads with a 1" overall length and .75" under-head length for proper spindle fitment Durable Steel Construction – Manufactured from quality steel for dependable strength and long service life in brake and suspension assemblies Wide GM Compatibility – Fits GM A-Body (Chevelle, GTO, Cutlass), F-Body (Camaro, Firebird), and X-Body (Nova, Ventura) vehicles Easy Installation – Hex-head design allows simple installation using standard hand tools when servicing or restoring front disc brake spindles These replacement backing plate upper spindle bolts fit OEM style 1964-1974 GM disc brake spindles. Bolt has 5/8"-18 RH threads with a 1" overall length and 3/4" underhead length. Fits the following applications: 1964-72 A-Body - Chevelle, Malibu, GTO, LeMans, 442, Cutlass, GS, Skylark. 1967-72 F-Body - Camaro, Firebird. 1968-74 X-Body - Nova, Apollo, Omega, Ventura.