The International Harvester IDI (from Indirect Injection) engine is a 4-stroke 8-cylinder Diesel engine used in International Harvester trucks, Ford F-Series pickups, and Ford E-Series vans from 1983 to 1994. The engine had two displacements: 420 cubic inches (6.9 litres), which was used in Ford trucks from 1983 until 1987, and 444 cubic inches (7.3 litres), which was used in Ford trucks from 1988 until 1994 (naturally aspirated) and in 1993 and 1994 (turbocharged). These engines were replaced in 1994.5 by the Navistar T444E (7.3 L) engine, which was also marketed under the Ford Power Stroke name.