1984 to 1995 601 602 603 Diesel Performance Enhancement
Produced from 1984 to 1993 these lighter weight aluminum head engines replaced the venerable cast iron 616 and 617 engines of the 1970's and early 1980's. Theses engines were more powerful and more fuel efficient. They did have a few teething problems but have proven to be very durable as long as they are treated and maintained properly.