For sale are a pair of GM BBC Aluminum Cylinder Heads, part number #3919842, originally installed on various models, including Corvettes, Chevelles, Novas, and Camaros equipped with the L89 option, as well as Corvettes with the L88 engine. These cylinder heads feature a semi-closed chamber design, notably used on 1968 L88 & L89 vehicles with both 396 and 427 engines, as well as all 1969 models ...