6.0L - 8-cyl ( Description: HD CLASSIC 6.0L 8-cyl Engine Code; Fuel: Gasoline; Engine Code: [U]; )
6.6L - 8-cyl ( Description: HD CLASSIC 6.6L 8-cyl Engine Code; Fuel: Diesel; Engine Code: [D]; )
8.1L - 8-cyl ( Description: HD CLASSIC 8.1L 8-cyl Engine Code; Fuel: Gasoline; Engine Code: [G]; )