GM LS engine piston ring set with 4.00 Inch/101.6 mm bore, 8 cylinders, Available in sizes: Standard, .005 over, .010 over, .020 over, and .030 over, Top ring - 1.50 mm groove, steel ring material, plasma moly ring surface treatment, 2nd ring - 1.50 mm groove, grey iron ring material, phosphate ring surface treatment, Oil ring - 3.00 mm groove, steel rail and stainless expander material, chrome rail ring surface treatment.