Comprehensive NURAL engine overhaul kit designed as a direct replacement for John Deere OEM part AR90550NNO. This kit features a 102mm bore and 35mm piston pin, ensuring precise fitment and optimal engine performance. It includes 6 cylinder liners, 6 pistons, 6 piston ring sets, 6 piston pins, 12 circlips, a complete upper engine gasket set, a complete lower engine gasket set, a connecting rod bearing set, a crankshaft bearing set, and a crankshaft thrust washer set. Engineered for durability and reliability, this kit is suitable for various John Deere agricultural machinery, including 4040, 4050, 4240, 4250, 4440, 4450, 4640, 4650, 4840, 4850, 8430, 8440, 8450, 8630, 8640, 8650 tractors, and 6620, 7720, 8820 combines.