Stainless/Black Shovelhead Rocker Box Split Oil LinesOld Stf Stainless case to rocker box oil lines for Harley Davidson Big Twin 1966 1984 These stainless oil lines are functional and beautiful! The split design routes oil to both rocker boxes immediately from startup, not sequentially from rear to front as the factory lines do, saving wear and tear on the rocker boxes and components within. The black fittings and stainless lines provide a unique contrasting look, too, whether your engine is natural