THOSE ARE FORDS STOCK INJECTORS RIGHT FROM THE FACTORY.... AS OTHERS WILL TELL YOU LISTEN TO THEM (mike them or even use a dowel rod) plugs love to come lose from heads .... will make a sound simular to noisey rocker arms on a push rod engine. GOOD LUCK , GET A DIABLOSPORT PREDATOR , PULLEY(s) AND ENJOY BEATING UP ON THE REST.
