All of our new parts are aftermarket replacements. Compatible with Ford Tractor(s) 800, 820, 840, 850, 900, 950, 960, 4000. Compatible with Ford Engine(s) 172 (Diesel). Diesel Engine with 5-ring pistons. Contains sleeve and piston kit, complete gasket set, connecting rod bushings and bearings, center, front and rear main bearings, intake and exhaust valves (plus guides, locks and springs). All States Ag Parts Item No.