R46471 AR49501 New Front Diesel Exhaust Manifold Fits John Deere Tractor 4320One New Aftermarket Replacement Front Diesel Exhaust Manifold Fits John Deere Tractor 4320 This front section exhaust manifold is a direct aftermarket replacement for the Fits John Deere (Fits JD) 4320 row crop tractor. The manifold is the front half of the two piece exhaust manifold assembly on the diesel engine, channeling combustion gases from the cylinder head to the exhaust system. It is cast for durability and resistance to the high temperatures