Comp Cams 54-455-11 LSR Cathedral Port Camshaft for 1997+ Gen III IV GM LS EnginesLSR Cathedral Port 215 223 Hydraulic Roller Cam for GM LS GEN III IV Very strong torque and excellent response. Works best in heavy vehicles, low rpm applications. Grind Number: 265Lr HR12 Engine Family: GM LS GEN III IV 3 Bolt 8 Cylinder (1997 2015) RPM Operating Range: 1,300 6,500 Cam Type: Hydraulic Roller Lifter Style: Hydraulic Roller Camshaft Series: LSR Cathedral Port Small Displacement Max Torque Camshaft Gear Attachment: 3 Bolt Valve Springs