OLDSMOBILE 400,425,455 OPEN PLENUM ALUMINUM INTAKE . THIS MANIFOLD IS PROBABLY THE BEST OLDSMOBILE MANIFOLD OUT THERE . IT HAS THE ULTIMATE DESIGN . THIS MANIFOLD CAN BE READY TO BOLT ON AN RUN WITH SQUARE BORE CARB . IT ALSO HAS CAST IN THE CASTING BUNGS FOR FUEL INJECTION WITH STAND-OFF POST TO MOUNT THE FUEL RAIL . NEW AND IMPROVED CASTINGS .