PLK163 New Std Piston Kit Fits John Deere 3010 3020 4010 4020 500 500A 500B +One New Aftermarket Replacement Standard Piston Kit Fits John Deere 4270 6404D Diesel Engines This standard bore piston kit (also known as a piston liner kit) is a direct aftermarket replacement for the Fits John Deere (Fits JD) 4270 and 6404D diesel engines. Designed for engine rebuild and overhaul applications, it restores proper cylinder compression and piston to wall clearance in worn or damaged cylinders. The 6404D is a 6 cylinder, 404 cubic inch