Made from high silicon enhanced 4032 alloy that has lower thermal expansion. Offset wrist pins for quieter operation. Cold extruded chrome moly steel wrist pins. This set includes 4 pistons, rings, pins and clips. Forged Piston Set 16v "ABF" 82.5mm (STD bore) (tall block) 11.8-1 CR. (Small end of rod needs to less than 23mm wide.) See rod part number IERV-15921.