6.6 LITER DIESEL. Belt tensioner bolt. PartQualifier: serp belt tnsr. serp belt tnsr. W/DUAL ALTERNATORS. A threaded rod with a drive head (such as hex, 12 point, torx, etc) on one end used to secure the Engine Support Rod to it's Mounting point. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Air Injection System Line to it's Mounting point. A/C Compressor Bolt. Accessory Drive Belt Idler Pulley Bolt. Alternator Adjusting Bracket Bolt. Alternator Bolt. Alternator Bracket Bolt. Automatic Transmission Mount Bolt. Belt Tensioner Bolt. Starter Bolt.