Product Info: Part: Engine Piston Piston Material: Aluminum Alloy Piston Head Type: Flat Piston Inside Diameter: 3.878 inches / 98.5 millimeters Skirt Length: 1.504 inches / 38.2 millimeters Piston Pin Length: 2.574 inches / 65.37 millimeters Ring Material: Steel Skirt Type: Partial Piston Pin Inside Diameter: 0.535 inches / 13.