Caterpillar Cat 3126 BEJ1-UP 3 valve Industrial.50mm bore IF4621B/42 IF4621B/42 Truck Applications Kits 2 piece pistons: Piston Skirt?s, Piston Crown?s Piston Pins, Piston Clips, Main Bearings, Rod Bearings, Thrust Washer, Upper Gasket Set & Oil Pan Gasket (Repair Sleeve?s are available for purchase)