Part Type: Accessory Drive Belt Idler Pulley. Belt Idler Pulley. Belt Type: Serpentine. 1991 GMC C3500 Engine: 7.4L V8; Position: Serpentine;. 1992 GMC C3500 Engine: 5.7L V8; Position: Serpentine;. 1992 GMC C3500 Engine: 7.4L V8; Position: Serpentine;.
