The road teaches a hard lesson: vibration is a thief. It loosens what is weak and exposes false strength. These wedge locking header bolts were shaped for that truth. Two faces of What could be causing a vibration in my small block Chevy engine between 2 2500 rpm? What could be causing the violent vibration in a Chevy 350 engine, resulting in a cracked bellhousing? What could be causing a vibration in my small block Chevy engine between 2 2500 rpm? Supercharged 638 Big Block Chevy Engine Engine Builder Magazine Understanding Vehicle Vibrations in Reverse and Drive Gear