4BT3.9 Cummins Oil Piston Ring 3932520 Parts Catalog Ref No. Part Name Part No. Required 1 Piston Pin 3934047 6 2 Connecting Rod Bearing 3939859 6 3 Connecting Rod Bearing 5302904 6 　 Engine Connecting Rod 4943979 6 4 Engine Connecting Rod 4943978 1 5 Bushing 4891178 1 6 Connecting Rod Cap Screw 4891179 2 7 Oil Piston Ring 3932520 …